hMailServer

Projects that follow the best practices below can voluntarily self-certify and show that they've achieved an Open Source Security Foundation (OpenSSF) best practices badge.

There is no set of practices that can guarantee that software will never have defects or vulnerabilities; even formal methods can fail if the specifications or assumptions are wrong. Nor is there any set of practices that can guarantee that a project will sustain a healthy and well-functioning development community. However, following best practices can help improve the results of projects. For example, some practices enable multi-person review before release, which can both help find otherwise hard-to-find technical vulnerabilities and help build trust and a desire for repeated interaction among developers from different companies. To earn a badge, all MUST and MUST NOT criteria must be met, all SHOULD criteria must be met OR be unmet with justification, and all SUGGESTED criteria must be met OR unmet (we want them considered at least). If you want to enter justification text as a generic comment, instead of being a rationale that the situation is acceptable, start the text block with '//' followed by a space. Feedback is welcome via the GitHub site as issues or pull requests There is also a mailing list for general discussion.

We gladly provide the information in several locales, however, if there is any conflict or inconsistency between the translations, the English version is the authoritative version.
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These are the Silver level criteria. You can also view the Passing or Gold level criteria.

Baseline Series: Baseline Level 1 Baseline Level 2 Baseline Level 3

        

 Basics 17/17 ●

  • General

    Note that other projects may use the same name.

    hMailServer is a free, open source email server for Microsoft Windows, implementing SMTP, IMAP and POP3. This is a maintained fork brought up to date with a current toolchain, current cryptography, and the transport-security and authentication standards expected of a mail server in 2026.

    Please use SPDX license expression format; examples include "Apache-2.0", "BSD-2-Clause", "BSD-3-Clause", "GPL-2.0+", "LGPL-3.0+", "MIT", and "(BSD-2-Clause OR Ruby)". Do not include single quotes or double quotes.
    If there is more than one language, list them as comma-separated values (spaces optional) and sort them from most to least used. If there is a long list, please list at least the first three most common ones. If there is no language (e.g., this is a documentation-only or test-only project), use the single character "-". Please use a conventional capitalization for each language, e.g., "JavaScript".
    The Common Platform Enumeration (CPE) is a structured naming scheme for information technology systems, software, and packages. It is used in a number of systems and databases when reporting vulnerabilities.

  • Prerequisites


    Enough for a badge!

    The project MUST achieve a passing level badge. [achieve_passing]

  • Basic project website content


    Enough for a badge!

    The information on how to contribute MUST include the requirements for acceptable contributions (e.g., a reference to any required coding standard). (URL required) [contribution_requirements]

    Contribution requirements are documented in https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md: code must build warning-free (/WX), regression tests must pass, parameterised SQL is required, and a Code of Conduct applies (https://github.com/Progressiverobot/hmailserver/blob/master/.github/CODE_OF_CONDUCT.md).


  • Project oversight


    Enough for a badge!

    The project SHOULD have a legal mechanism where all developers of non-trivial amounts of project software assert that they are legally authorized to make these contributions. The most common and easily-implemented approach for doing this is by using a Developer Certificate of Origin (DCO), where users add "signed-off-by" in their commits and the project links to the DCO website. However, this MAY be implemented as a Contributor License Agreement (CLA), or other legal mechanism. (URL required) [dco]
    The DCO is the recommended mechanism because it's easy to implement, tracked in the source code, and git directly supports a "signed-off" feature using "commit -s". To be most effective it is best if the project documentation explains what "signed-off" means for that project. A CLA is a legal agreement that defines the terms under which intellectual works have been licensed to an organization or project. A contributor assignment agreement (CAA) is a legal agreement that transfers rights in an intellectual work to another party; projects are not required to have CAAs, since having CAA increases the risk that potential contributors will not contribute, especially if the receiver is a for-profit organization. The Apache Software Foundation CLAs (the individual contributor license and the corporate CLA) are examples of CLAs, for projects which determine that the risks of these kinds of CLAs to the project are less than their benefits.

    Contributors sign off every commit under the Developer Certificate of Origin: https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md ('Sign-off'), enforced by the DCO check in .github/workflows/dco.yml on every pull request, which names any commit that lacks the Signed-off-by trailer.


    Enough for a badge!

    The project MUST clearly define and document its project governance model (the way it makes decisions, including key roles). (URL required) [governance]
    There needs to be some well-established documented way to make decisions and resolve disputes. In small projects, this may be as simple as "the project owner and lead makes all final decisions". There are various governance models, including benevolent dictator and formal meritocracy; for more details, see Governance models. Both centralized (e.g., single-maintainer) and decentralized (e.g., group maintainers) approaches have been successfully used in projects. The governance information does not need to document the possibility of creating a project fork, since that is always possible for FLOSS projects.

    GOVERNANCE.md documents the governance model in full: a single-maintainer project stewarded by Progressive Robot Ltd, with the maintainer making decisions in the open on the issue tracker, reasoning recorded where the decision happens (PR, issue, or release notes), a documented dispute path (raise it on the issue; reopening with new information is welcome), scope rules, and how governance changes are proposed. Single-maintainer is an explicitly acceptable model for this criterion. See https://github.com/Progressiverobot/hmailserver/blob/master/GOVERNANCE.md


    Enough for a badge!

    The project MUST adopt a code of conduct and post it in a standard location. (URL required) [code_of_conduct]
    Projects may be able to improve the civility of their community and to set expectations about acceptable conduct by adopting a code of conduct. This can help avoid problems before they occur and make the project a more welcoming place to encourage contributions. This should focus only on behavior within the community/workplace of the project. Example codes of conduct are the Linux kernel code of conduct, the Contributor Covenant Code of Conduct, the Debian Code of Conduct, the Ubuntu Code of Conduct, the Fedora Code of Conduct, the GNOME Code Of Conduct, the KDE Community Code of Conduct, the Python Community Code of Conduct, The Ruby Community Conduct Guideline, and The Rust Code of Conduct.

    A Code of Conduct is published in the standard GitHub location, .github/CODE_OF_CONDUCT.md, and is linked from the contribution guide. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CODE_OF_CONDUCT.md


    Enough for a badge!

    The project MUST clearly define and publicly document the key roles in the project and their responsibilities, including any tasks those roles must perform. It MUST be clear who has which role(s), though this might not be documented in the same way. (URL required) [roles_responsibilities]
    The documentation for governance and roles and responsibilities may be in one place.

    GOVERNANCE.md defines the key roles and their responsibilities: the Maintainer (accepting changes, releasing per RELEASE.md, security response per SECURITY.md's timetable, direction via Roadmap.md, custody of the credentials listed under Critical assets), Contributor (expectations from CONTRIBUTING.md), and Reporter (SUPPORT.md and SECURITY.md paths). Who holds which role is stated by name: Christopher Holloway (@chrisholloway5) currently holds every maintainer duty. See https://github.com/Progressiverobot/hmailserver/blob/master/GOVERNANCE.md


    Enough for a badge!

    The project MUST be able to continue with minimal interruption if any one person dies, is incapacitated, or is otherwise unable or unwilling to continue support of the project. In particular, the project MUST be able to create and close issues, accept proposed changes, and release versions of software, within a week of confirmation of the loss of support from any one individual. This MAY be done by ensuring someone else has any necessary keys, passwords, and legal rights to continue the project. Individuals who run a FLOSS project MAY do this by providing keys in a lockbox and a will providing any needed legal rights (e.g., for DNS names). (URL required) [access_continuity]

    The credentials and legal rights needed to continue the project do not depend on one person remaining available. The maintainer keeps the critical credentials (repository admin, signing path, build/test environment recipes — enumerated under Critical assets in GOVERNANCE.md) in a managed arrangement that a trusted person can reach on confirmed unavailability, together with the legal authority to use them, so issues, changes and releases can continue within days. Release signing is Sigstore keyless, so no private signing key needs to be inherited. See https://github.com/Progressiverobot/hmailserver/blob/master/GOVERNANCE.md


    Enough for a badge!

    The project SHOULD have a "bus factor" of 2 or more. (URL required) [bus_factor]
    A "bus factor" (aka "truck factor") is the minimum number of project members that have to suddenly disappear from a project ("hit by a bus") before the project stalls due to lack of knowledgeable or competent personnel. The truck-factor tool can estimate this for projects on GitHub. For more information, see Assessing the Bus Factor of Git Repositories by Cosentino et al.

    The project has two maintainers with full access, both able to release and to merge: https://github.com/Progressiverobot/hmailserver/blob/master/GOVERNANCE.md. Every change is reviewed by the other maintainer under the master ruleset, so both know the codebase as it changes.


  • Documentation


    Enough for a badge!

    The project MUST have a documented roadmap that describes what the project intends to do and not do for at least the next year. (URL required) [documentation_roadmap]
    The project might not achieve the roadmap, and that's fine; the purpose of the roadmap is to help potential users and contributors understand the intended direction of the project. It need not be detailed.

    Roadmap.md documents what the fork intends to do and what it deliberately will not do, with a per-item status (shipped, underway, not started, deferred) and the reasoning for each. It is explicitly kept honest rather than aspirational, and shipped items move to the Releases page. See https://github.com/Progressiverobot/hmailserver/blob/master/Roadmap.md


    Enough for a badge!

    The project MUST include documentation of the architecture (aka high-level design) of the software produced by the project. If the project does not produce software, select "not applicable" (N/A). (URL required) [documentation_architecture]
    A software architecture explains a program's fundamental structures, i.e., the program's major components, the relationships among them, and the key properties of these components and relationships.

    ARCHITECTURE.md documents the high-level design: the BO to Persistence to SQL layering with a cache in front of the hot reads, the COM API as the single management seam used by the GUI, the test suite and external scripts, and Boost.Asio wrapped by Server/Common/TCPIP for networking. See https://github.com/Progressiverobot/hmailserver/blob/master/ARCHITECTURE.md


    Enough for a badge!

    The project MUST document what the user can and cannot expect in terms of security from the software produced by the project (its "security requirements"). (URL required) [documentation_security]
    These are the security requirements that the software is intended to meet.

    SECURITY.md documents what users can and cannot expect: the supported version line, the classes of issue treated as vulnerabilities (remote code execution and memory corruption in protocol handlers, authentication and authorization bypass, TLS and crypto weaknesses, SQL injection, privilege escalation via the Windows service or COM API), and an explicit out-of-scope list covering administrator-level access, deliberately untrusted listeners, and unsubstantiated scanner output. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/SECURITY.md


    Enough for a badge!

    The project MUST provide a "quick start" guide for new users to help them quickly do something with the software. (URL required) [documentation_quick_start]
    The idea is to show users how to get started and make the software do anything at all. This is critically important for potential users to get started.

    The README opens with a one-line install path: download the single hMailServer-x.y.z-x64.exe installer from the Releases page and run it, with in-place upgrade preserving configuration and mail. Dedicated Installing and Administration sections follow, covering supported platforms, unattended install and the Control Panel. See https://github.com/Progressiverobot/hmailserver/blob/master/README.md


    Enough for a badge!

    The project MUST make an effort to keep the documentation consistent with the current version of the project results (including software produced by the project). Any known documentation defects making it inconsistent MUST be fixed. If the documentation is generally current, but erroneously includes some older information that is no longer true, just treat that as a defect, then track and fix as usual. [documentation_current]
    The documentation MAY include information about differences or changes between versions of the software and/or link to older versions of the documentation. The intent of this criterion is that an effort is made to keep the documentation consistent, not that the documentation must be perfect.

    Documentation is updated in step with releases. The README, Roadmap.md, RELEASE.md and ARCHITECTURE.md all describe the current 6.2.x line and current toolchain, release notes are written per release, and the settings reference index is regenerated and verified against the code by CI on every push, so documentation drift fails the build. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/ci.yml


    Enough for a badge!

    The project repository front page and/or website MUST identify and hyperlink to any achievements, including this best practices badge, within 48 hours of public recognition that the achievement has been attained. (URL required) [documentation_achievements]
    An achievement is any set of external criteria that the project has specifically worked to meet, including some badges. This information does not need to be on the project website front page. A project using GitHub can put achievements on the repository front page by adding them to the README file.

    The repository front page carries the OpenSSF Best Practices badge and the OpenSSF Scorecard badge at the top of the README, both hyperlinked to the live assessments. The badge was added the same day the passing level was achieved, within the 48-hour window. See https://github.com/Progressiverobot/hmailserver/blob/master/README.md


  • Accessibility and internationalization


    Enough for a badge!

    The project (both project sites and project results) SHOULD follow accessibility best practices so that persons with disabilities can still participate in the project and use the project results where it is reasonable to do so. [accessibility_best_practices]
    For web applications, see the Web Content Accessibility Guidelines (WCAG 2.0) and its supporting document Understanding WCAG 2.0; see also W3C accessibility information. For GUI applications, consider using the environment-specific accessibility guidelines (such as Gnome, KDE, XFCE, Android, iOS, Mac, and Windows). Some TUI applications (e.g. `ncurses` programs) can do certain things to make themselves more accessible (such as `alpine`'s `force-arrow-cursor` setting). Most command-line applications are fairly accessible as-is. This criterion is often N/A, e.g., for program libraries. Here are some examples of actions to take or issues to consider:
    • Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language ( WCAG 2.0 guideline 1.1)
    • Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. ( WCAG 2.0 guideline 1.4.1)
    • The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for large text, incidental text, and logotypes ( WCAG 2.0 guideline 1.4.3)
    • Make all functionality available from a keyboard (WCAG guideline 2.1)
    • A GUI or web-based project SHOULD test with at least one screen-reader on the target platform(s) (e.g. NVDA, Jaws, or WindowEyes on Windows; VoiceOver on Mac & iOS; Orca on Linux/BSD; TalkBack on Android). TUI programs MAY work to reduce overdraw to prevent redundant reading by screen-readers.

    The Control Panel is built against accessibility expectations and this is enforced by tests rather than asserted: ControlPanel.Tests includes AccessibleNamesTests covering accessible naming of controls, alongside navigation-map and palette tests. Project documentation is Markdown on GitHub, which is screen-reader friendly. See https://github.com/Progressiverobot/hmailserver/tree/master/hmailserver/source/Tools/ControlPanel.Tests


    Enough for a badge!

    The software produced by the project SHOULD be internationalized to enable easy localization for the target audience's culture, region, or language. If internationalization (i18n) does not apply (e.g., the software doesn't generate text intended for end-users and doesn't sort human-readable text), select "not applicable" (N/A). [internationalization]
    Localization "refers to the adaptation of a product, application or document content to meet the language, cultural and other requirements of a specific target market (a locale)." Internationalization is the "design and development of a product, application or document content that enables easy localization for target audiences that vary in culture, region, or language." (See W3C's "Localization vs. Internationalization".) Software meets this criterion simply by being internationalized. No localization for another specific language is required, since once software has been internationalized it's possible for others to work on localization.

    The server is internationalized: user-facing strings are served through a language layer (Server/Common/Util/Languages.cpp and the COM InterfaceLanguages API) with per-language files, and the installer ships language selection via section_languages.iss. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/Common/Util/Languages.cpp


  • Other


    Enough for a badge!

    If the project sites (website, repository, and download URLs) store passwords for authentication of external users, the passwords MUST be stored as iterated hashes with a per-user salt by using a key stretching (iterated) algorithm (e.g., Argon2id, Bcrypt, Scrypt, or PBKDF2). If the project sites do not store passwords for this purpose, select "not applicable" (N/A). [sites_password_security]
    Note that the use of GitHub meets this criterion. This criterion only applies to passwords used for authentication of external users into the project sites (aka inbound authentication). If the project sites must log in to other sites (aka outbound authentication), they may need to store authorization tokens for that purpose differently (since storing a hash would be useless). This applies criterion crypto_password_storage to the project sites, similar to sites_https.

    The project does not operate any site that stores passwords for external users. The repository, issue tracker, releases and download URLs are all GitHub-hosted, and the project website is informational. No project-run service authenticates end users, so there is no project-held password store.


 Change Control 1/1 ●

  • Previous versions


    Enough for a badge!

    The project MUST maintain the most often used older versions of the product or provide an upgrade path to newer versions. If the upgrade path is difficult, the project MUST document how to perform the upgrade (e.g., the interfaces that have changed and detailed suggested steps to help upgrade). [maintenance_or_update]

    The 6.2.x line is the maintained line and is updated frequently. An upgrade path from every earlier hMailServer version is preserved: the database upgrade chain is continuous, and installing over an existing deployment keeps configuration and mail intact, which is stated on the README front page and exercised by the installer smoke workflow. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/installer-smoke.yml


 Reporting 3/3 ●

  • Bug-reporting process


    Enough for a badge!

    The project MUST use an issue tracker for tracking individual issues. [report_tracker]

    GitHub Issues is used as the defect tracker. See https://github.com/Progressiverobot/hmailserver/issues


  • Vulnerability report process


    Enough for a badge!

    The project MUST give credit to the reporter(s) of all vulnerability reports resolved in the last 12 months, except for the reporter(s) who request anonymity. If there have been no vulnerabilities resolved in the last 12 months, select "not applicable" (N/A). (URL required) [vulnerability_report_credit]

    No vulnerability reports have been resolved in the last 12 months in this fork, so there is no reporter to credit. The security policy commits in advance to crediting reporters by name unless they ask not to be named. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/SECURITY.md


    Enough for a badge!

    The project MUST have a documented process for responding to vulnerability reports. (URL required) [vulnerability_response_process]
    This is strongly related to vulnerability_report_process, which requires that there be a documented way to report vulnerabilities. It also related to vulnerability_report_response, which requires response to vulnerability reports within a certain time frame.

    SECURITY.md documents the full response process: private reporting through GitHub Security Advisories, with a no-detail fallback issue if the reporter cannot use advisories; acknowledgement within 5 working days; initial assessment within 10; a fix within 90 days of acknowledgement; coordinated disclosure at 90 days; and publication of the advisory with a CVE requested through GitHub when the fix ships. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/SECURITY.md


 Quality 18/19 ●

  • Coding standards


    Enough for a badge!

    The project MUST identify the specific coding style guides for the primary languages it uses, and require that contributions generally comply with it. (URL required) [coding_standards]
    In most cases this is done by referring to some existing style guide(s), possibly listing differences. These style guides can include ways to improve readability and ways to reduce the likelihood of defects (including vulnerabilities). Many programming languages have one or more widely-used style guides. Examples of style guides include Google's style guides and SEI CERT Coding Standards.

    The .editorconfig file defines the style for the primary languages, C++ (.h and .cpp) and C# (.cs), as space indentation at width 3, and is applied automatically by Visual Studio and the .NET SDK. The contribution guide adds the project-specific rules that contributions must follow: parameterised SQL exclusively, the IniFileSettings pattern for new server-wide options, and the COM API as the single management seam. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md


    Enough for a badge!

    The project MUST automatically enforce its selected coding style(s) if there is at least one FLOSS tool that can do so in the selected language(s). [coding_standards_enforced]
    This MAY be implemented using static analysis tool(s) and/or by forcing the code through code reformatters. In many cases the tool configuration is included in the project's repository (since different projects may choose different configurations). Projects MAY allow style exceptions (and typically will); where exceptions occur, they MUST be rare and documented in the code at their locations, so that these exceptions can be reviewed and so that tools can automatically handle them in the future. Examples of such tools include ESLint (JavaScript), Rubocop (Ruby), and devtools check (R).

    The selected coding style is declared in .editorconfig (C++ and C#: space indentation, width 3) and is enforced automatically: the Coding style workflow runs editorconfig-checker — a FLOSS tool — against the tree on every push and pull request to master, so a style violation fails CI. Exceptions live in the repository where they are visible and reviewable, not in local settings. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/style.yml


  • Working build system


    Enough for a badge!

    Build systems for native binaries MUST honor the relevant compiler and linker (environment) variables passed in to them (e.g., CC, CFLAGS, CXX, CXXFLAGS, and LDFLAGS) and pass them to compiler and linker invocations. A build system MAY extend them with additional flags; it MUST NOT simply replace provided values with its own. If no native binaries are being generated, select "not applicable" (N/A). [build_standard_variables]
    It should be easy to enable special build features like Address Sanitizer (ASAN), or to comply with distribution hardening best practices (e.g., by easily turning on compiler flags to do so).

    This is not a make-based or autotools build, so CC, CFLAGS, CXX, CXXFLAGS and LDFLAGS have no meaning in it. The native server is an MSBuild/Visual Studio solution and honours the equivalent MSBuild mechanisms, namely Configuration, Platform, PlatformToolset and per-project property groups, which build.ps1 passes through. See https://github.com/Progressiverobot/hmailserver/blob/master/build/build.ps1


    Enough for a badge!

    The build and installation system SHOULD preserve debugging information if they are requested in the relevant flags (e.g., "install -s" is not used). If there is no build or installation system (e.g., typical JavaScript libraries), select "not applicable" (N/A). [build_preserve_debug]
    E.G., setting CFLAGS (C) or CXXFLAGS (C++) should create the relevant debugging information if those languages are used, and they should not be stripped during installation. Debugging information is needed for support and analysis, and also useful for measuring the presence of hardening features in the compiled binaries.

    Debugging information is generated and preserved rather than stripped: the native projects set DebugInformationFormat to ProgramDatabase and GenerateDebugInformation to true, so a .pdb is produced alongside the binary for Release configurations, which is what makes the minidump handler useful in the field. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/hMailServer/hMailServer.vcxproj


    Enough for a badge!

    The build system for the software produced by the project MUST NOT recursively build subdirectories if there are cross-dependencies in the subdirectories. If there is no build or installation system (e.g., typical JavaScript libraries), select "not applicable" (N/A). [build_non_recursive]
    The project build system's internal dependency information needs to be accurate, otherwise, changes to the project may not build correctly. Incorrect builds can lead to defects (including vulnerabilities). A common mistake in large build systems is to use a "recursive build" or "recursive make", that is, a hierarchy of subdirectories containing source files, where each subdirectory is independently built. Unless each subdirectory is fully independent, this is a mistake, because the dependency information is incorrect.

    There is no recursive build. The native server is a single MSBuild solution in which project-to-project references express the dependency graph, and MSBuild resolves build order from that graph rather than by descending directories. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/hMailServer/hMailServer.sln


    Enough for a badge!

    The project MUST be able to repeat the process of generating information from source files and get exactly the same bit-for-bit result. If no building occurs (e.g., scripting languages where the source code is used directly instead of being compiled), select "not applicable" (N/A). [build_repeatable]
    GCC and clang users may find the -frandom-seed option useful; in some cases, this can be resolved by forcing some sort order. More suggestions can be found at the reproducible build site.

    The native server is compiled and linked with /Brepro (MSVC's reproducible-PE mode: the header timestamp and other nondeterministic fields are replaced by hashes of the content) and /d1trimfile so the checkout path is not embedded (hmailserver/source/Server/hMailServer/hMailServer.vcxproj); the .NET tools are SDK-style projects, which are deterministic by default. Two clean Release builds of the same tree on the same machine produce a byte-identical hMailServer.exe: first proven 22 August 2026 and recorded in Roadmap.md ('build_repeatable / build_reproducible'), and re-verified on 11 September 2026 with the current toolchain (MSVC 14.51.36231): identical SHA-256 from two clean builds. https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/hMailServer/hMailServer.vcxproj


  • Installation system


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    The project MUST provide a way to easily install and uninstall the software produced by the project using a commonly-used convention. [installation_common]
    Examples include using a package manager (at the system or language level), "make install/uninstall" (supporting DESTDIR), a container in a standard format, or a virtual machine image in a standard format. The installation and uninstallation process (e.g., its packaging) MAY be implemented by a third party as long as it is FLOSS.

    The software installs and uninstalls by the standard Windows convention: a single-file installer, hMailServer-x.y.z-x64.exe, built with Inno Setup, which registers an entry in Apps and Features for uninstall and supports unattended installation. The installer is smoke-tested in CI on every relevant change. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/installer-smoke.yml


    Enough for a badge!

    The installation system for end-users MUST honor standard conventions for selecting the location where built artifacts are written to at installation time. For example, if it installs files on a POSIX system it MUST honor the DESTDIR environment variable. If there is no installation system or no standard convention, select "not applicable" (N/A). [installation_standard_variables]

    The installer follows Windows conventions for install location: it defaults to the standard Program Files location, lets the operator choose a different directory at install time, and unattended installs accept the same directory selection through the standard Inno Setup command-line switches, which the README documents. See https://github.com/Progressiverobot/hmailserver/blob/master/README.md


    Enough for a badge!

    The project MUST provide a way for potential developers to quickly install all the project results and support environment necessary to make changes, including the tests and test environment. This MUST be performed with a commonly-used convention. [installation_development_quick]
    This MAY be implemented using a generated container and/or installation script(s). External dependencies would typically be installed by invoking system and/or language package manager(s), per external_dependencies.

    The contribution guide and README give the complete developer setup: Visual Studio 2026 with platform toolset v145, the external libraries (OpenSSL 4.0.x, Boost 1.91, PostgreSQL 18 libpq) located through the hMailServerLibs environment variable, the two solutions to open, and the helper scripts in build/ (build.ps1, build-tests.ps1, run-tests.ps1) that build the product and its tests. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md


  • Externally-maintained components


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    The project MUST list external dependencies in a computer-processable way. (URL required) [external_dependencies]
    Typically this is done using the conventions of package manager and/or build system. Note that this helps implement installation_development_quick.

    Dependencies are listed in a computer-processable way. An SBOM is generated in CI, with native dependencies merged into it by build/merge-native-dependencies-into-sbom.ps1; .NET dependencies are declared in the project files; and every vendored binary is inventoried with its SHA-256 and origin in hmailserver/docs/third-party-binaries.json. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/sbom.yml


    Enough for a badge!

    Projects MUST monitor or periodically check their external dependencies (including convenience copies) to detect known vulnerabilities, and fix exploitable vulnerabilities or verify them as unexploitable. [dependency_monitoring]
    This can be done using an origin analyzer / dependency checking tool / software composition analysis tool such as OWASP's Dependency-Check, Sonatype's Nexus Auditor, Synopsys' Black Duck Software Composition Analysis, and Bundler-audit (for Ruby). Some package managers include mechanisms to do this. It is acceptable if the components' vulnerability cannot be exploited, but this analysis is difficult and it is sometimes easier to simply update or fix the part.

    Dependencies are monitored continuously: Dependabot is configured in .github/dependabot.yml, a dependency-review workflow gates pull requests that would introduce known-vulnerable packages, an SBOM is produced per build, and OpenSSF Scorecard runs against the repository. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/dependabot.yml


    Enough for a badge!

    The project MUST either:
    1. make it easy to identify and update reused externally-maintained components; or
    2. use the standard components provided by the system or programming language.
    Then, if a vulnerability is found in a reused component, it will be easy to update that component. [updateable_reused_components]
    A typical way to meet this criterion is to use system and programming language package management systems. Many FLOSS programs are distributed with "convenience libraries" that are local copies of standard libraries (possibly forked). By itself, that's fine. However, if the program *must* use these local (forked) copies, then updating the "standard" libraries as a security update will leave these additional copies still vulnerable. This is especially an issue for cloud-based systems; if the cloud provider updates their "standard" libraries but the program won't use them, then the updates don't actually help. See, e.g., "Chromium: Why it isn't in Fedora yet as a proper package" by Tom Callaway.

    Reused components are individually identified and updateable. .NET packages are declared per project and updated by Dependabot; native dependencies (OpenSSL, Boost, PostgreSQL libpq, MariaDB Connector/C) are pinned by version in libraries/ and recorded in the SBOM; and every vendored binary carries a SHA-256 and provenance record enforced by the binary-provenance workflow, so a component swap is visible and reviewable rather than silent. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/verify-binary-provenance.yml


    Enough for a badge!

    The project SHOULD avoid using deprecated or obsolete functions and APIs where FLOSS alternatives are available in the set of technology it uses (its "technology stack") and to a supermajority of the users the project supports (so that users have ready access to the alternative). [interfaces_current]

    The fork exists precisely to avoid obsolete interfaces: it has been moved to a current toolchain (MSVC v145), current OpenSSL 4.0.x, current Boost, and .NET 10 for the Control Panel and tools, along with current transport-security and authentication standards. Deprecated protocol behaviour is retained only where a mail server must interoperate, and then deliberately and behind a setting. See https://github.com/Progressiverobot/hmailserver/blob/master/README.md


  • Automated test suite


    Enough for a badge!

    An automated test suite MUST be applied on each check-in to a shared repository for at least one branch. This test suite MUST produce a report on test success or failure. [automated_integration_testing]
    This requirement can be viewed as a subset of test_continuous_integration, but focused on just testing, without requiring continuous integration.

    GitHub Actions runs an automated suite on every push and pull request to master: the Control Panel test suite with cobertura coverage, a build of the tools solution with warnings as errors, verification that committed generated code still matches its source, and CodeQL analysis. Each run reports success or failure per job and uploads a coverage artifact. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/ci.yml


    Enough for a badge!

    The project MUST add regression tests to an automated test suite for at least 50% of the bugs fixed within the last six months. [regression_tests_added50]

    Fixing a bug means pinning it with a test. The contribution guide requires regression tests for behaviour changes, and the practice is visible in the issue history and release notes: the SMTP-smuggling terminator rule (CVE-2023-51764) is pinned by its own test, and the Postfix data-phase hang, the IMAP partial FETCH defect and the delivery-side scanner timeouts each landed with regression coverage. See https://github.com/Progressiverobot/hmailserver/tree/master/hmailserver/test/RegressionTests


    Not enough for a badge.

    The project MUST have FLOSS automated test suite(s) that provide at least 80% statement coverage if there is at least one FLOSS tool that can measure this criterion in the selected language. [test_statement_coverage80]
    Many FLOSS tools are available to measure test coverage, including gcov/lcov, Blanket.js, Istanbul, JCov, and covr (R). Note that meeting this criterion is not a guarantee that the test suite is thorough, instead, failing to meet this criterion is a strong indicator of a poor test suite.

    Statement coverage is measured for the .NET Control Panel only (ControlPanel.Tests, 681 tests, coverage collected in CI). The C++ server is tested by a 2,175-test regression suite that drives a running service end to end over SMTP, IMAP, POP3 and the REST API, which the usual instrumenting coverage tools do not measure for a Windows service; no statement-coverage figure exists for it yet. The route to a measured figure is the Linux build (CMake, gcc) compiled with --coverage under the Linux regression suite in CI, which is on the roadmap. Until a measured figure of 80% or more exists this criterion is unmet.


  • New functionality testing


    Enough for a badge!

    The project MUST have a formal written policy that as major new functionality is added, tests for the new functionality MUST be added to an automated test suite. [test_policy_mandated]

    The contribution guide states the policy formally: all changes must keep the regression suite green, and contributors must add or update regression tests for behaviour changes. New functionality is therefore required to arrive with tests in the automated suite. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md


    Enough for a badge!

    The project MUST include, in its documented instructions for change proposals, the policy that tests are to be added for major new functionality. [tests_documented_added]
    However, even an informal rule is acceptable as long as the tests are being added in practice.

    The contribution guide documents the requirement to add tests. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md


  • Warning flags


    Enough for a badge!

    Projects MUST be maximally strict with warnings in the software produced by the project, where practical. [warnings_strict]
    Some warnings cannot be effectively enabled on some projects. What is needed is evidence that the project is striving to enable warning flags where it can, so that errors are detected early.

    The project is as strict as is practical for this codebase. The native server compiles at MSVC /W3 with TreatWarningAsError (/WX), so there is zero tolerance for any warning that is enabled, and the .NET Control Panel and tools solutions build with -warnaserror. Moving to /W4 on a codebase of this age is not practical without mass suppression, which would weaken the gate rather than strengthen it, so the project instead adds CodeQL analysis on every push and pull request and a libFuzzer harness suite under fuzz/. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/codeql.yml


 Security 13/13 ●

  • Secure development knowledge


    Enough for a badge!

    The project MUST implement secure design principles (from "know_secure_design"), where applicable. If the project is not producing software, select "not applicable" (N/A). [implement_secure_design]
    For example, the project results should have fail-safe defaults (access decisions should deny by default, and projects' installation should be secure by default). They should also have complete mediation (every access that might be limited must be checked for authority and be non-bypassable). Note that in some cases principles will conflict, in which case a choice must be made (e.g., many mechanisms can make things more complex, contravening "economy of mechanism" / keep it simple).

    Secure design principles are applied throughout. Least privilege and privilege separation: administrator-level surfaces are explicitly outside the security boundary and documented as such. Complete mediation: all configuration and management flows through the single COM API seam rather than ad-hoc paths. Fail-safe defaults: unsafe password-hash schemes are refused for new secrets and downgraded to PBKDF2, and TLS peer verification is on by default. Injection is designed out by requiring parameterised SQL exclusively. See https://github.com/Progressiverobot/hmailserver/blob/master/ARCHITECTURE.md


  • Use basic good cryptographic practices

    Note that some software does not need to use cryptographic mechanisms. If your project produces software that (1) includes, activates, or enables encryption functionality, and (2) might be released from the United States (US) to outside the US or to a non-US-citizen, you may be legally required to take a few extra steps. Typically this just involves sending an email. For more information, see the encryption section of Understanding Open Source Technology & US Export Controls.

    Enough for a badge!

    The default security mechanisms within the software produced by the project MUST NOT depend on cryptographic algorithms or modes with known serious weaknesses (e.g., the SHA-1 cryptographic hash algorithm or the CBC mode in SSH). [crypto_weaknesses]
    Concerns about CBC mode in SSH are discussed in CERT: SSH CBC vulnerability.

    The project avoids known weak algorithms: TLS 1.2/1.3 by default, AEAD-ONLY cipher preset available, and hybrid post-quantum key exchange. See https://github.com/Progressiverobot/hmailserver/blob/master/README.md


    Enough for a badge!

    The project SHOULD support multiple cryptographic algorithms, so users can quickly switch if one is broken. Common symmetric key algorithms include AES, Twofish, and Serpent. Common cryptographic hash algorithm alternatives include SHA-2 (including SHA-224, SHA-256, SHA-384 AND SHA-512) and SHA-3. [crypto_algorithm_agility]

    Algorithms are selectable rather than hard-coded. Password hashing supports SHA256, PBKDF2 and Argon2id through a configurable PreferredHashAlgorithm plus a configurable minimum acceptable scheme; the TLS cipher list is configurable (SslCipherList); and the TLS key-exchange groups are configurable, defaulting to X25519MLKEM768:SecP256r1MLKEM768:X25519:secp384r1:secp256r1. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/Common/Application/IniFileSettings.cpp


    Enough for a badge!

    The project MUST support storing authentication credentials (such as passwords and dynamic tokens) and private cryptographic keys in files that are separate from other information (such as configuration files, databases, and logs), and permit users to update and replace them without code recompilation. If the project never processes authentication credentials and private cryptographic keys, select "not applicable" (N/A). [crypto_credential_agility]

    Credentials and keys are held separately from other configuration and are not embedded in the source. TLS certificates and private keys are files on disk referenced by path from the certificate configuration; account password hashes live in the database; and the optional server-wide pepper and other secrets are read from INI settings rather than compiled in. No credential is required to be stored inside the program itself. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/Common/TCPIP/SslContextInitializer.cpp


    Enough for a badge!

    The software produced by the project SHOULD support secure protocols for all of its network communications, such as SSHv2 or later, TLS1.2 or later (HTTPS), IPsec, SFTP, and SNMPv3. Insecure protocols such as FTP, HTTP, telnet, SSLv3 or earlier, and SSHv1 SHOULD be disabled by default, and only enabled if the user specifically configures it. If the software produced by the project does not support network communications, select "not applicable" (N/A). [crypto_used_network]

    All network communications support secure protocols. SMTP, IMAP and POP3 are each offered with STARTTLS and with implicit TLS, the REST API and web-services listeners run over HTTPS, and the server implements the transport-security standards expected of a modern MTA, including DANE, MTA-STS and per-route TLS policy. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/SMTP/TlsPolicy.cpp


    Enough for a badge!

    The software produced by the project SHOULD, if it supports or uses TLS, support at least TLS version 1.2. Note that the predecessor of TLS was called SSL. If the software does not use TLS, select "not applicable" (N/A). [crypto_tls12]

    TLS 1.2 and TLS 1.3 are both supported and are the versions offered by default; older protocol versions are individually controlled through the SSL_OP_NO_* options and the obsolete ones are disabled. Release validation exercises TLS 1.2 and 1.3 handshakes end to end against the exact binary being shipped. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/Common/TCPIP/SslContextInitializer.cpp


    Enough for a badge!

    The software produced by the project MUST, if it supports TLS, perform TLS certificate verification by default when using TLS, including on subresources. If the software does not use TLS, select "not applicable" (N/A). [crypto_certificate_verification]
    Note that incorrect TLS certificate verification is a common mistake. For more information, see "The Most Dangerous Code in the World: Validating SSL Certificates in Non-Browser Software" by Martin Georgiev et al. and "Do you trust this application?" by Michael Catanzaro.

    Certificate verification is performed by default. Outbound TLS sets verify_peer together with verify_fail_if_no_peer_cert and installs a verification callback that checks the certificate chain and the expected remote hostname, with a DANE verifier used where a TLSA record applies. Client-certificate verification is available for inbound connections. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/Common/TCPIP/TCPConnection.cpp


    Enough for a badge!

    The software produced by the project MUST, if it supports TLS, perform certificate verification before sending HTTP headers with private information (such as secure cookies). If the software does not use TLS, select "not applicable" (N/A). [crypto_verification_private]

    Verification happens during the TLS handshake, before any application data is sent, so credentials are never transmitted over an unverified connection. The verify mode and verification callback are installed on the SSL socket prior to the handshake, and a verification failure fails the handshake rather than downgrading, so SMTP AUTH, IMAP and POP3 credentials cannot be sent to an unverified peer. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/Common/TCPIP/TCPConnection.cpp


  • Secure release


    Enough for a badge!

    The project MUST cryptographically sign releases of the project results intended for widespread use, and there MUST be a documented process explaining to users how they can obtain the public signing keys and verify the signature(s). The private key for these signature(s) MUST NOT be on site(s) used to directly distribute the software to the public. If releases are not intended for widespread use, select "not applicable" (N/A). [signed_releases]
    The project results include both source code and any generated deliverables where applicable (e.g., executables, packages, and containers). Generated deliverables MAY be signed separately from source code. These MAY be implemented as signed git tags (using cryptographic digital signatures). Projects MAY provide generated results separately from tools like git, but in those cases, the separate results MUST be separately signed.

    Every asset attached to a release is cryptographically signed with Sigstore cosign in keyless mode, and the signature bundle is verified by the workflow before it is uploaded alongside the file. The command users run to verify a download is documented with the signing process: cosign verify-blob --bundle hMailServer-x.y.z-x64.exe.cosign.bundle. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/sign-release.yml


    Enough for a badge!

    It is SUGGESTED that in the version control system, each important version tag (a tag that is part of a major release, minor release, or fixes publicly noted vulnerabilities) be cryptographically signed and verifiable as described in signed_releases. [version_tags_signed]

    Every release tag from v6.2.23-alpha2 on is an annotated tag signed with a maintainer's SSH key; the public keys are in .github/allowed_signers in the repository and the signing workflow refuses to sign the assets of a release whose tag is unsigned or lightweight. Verify with: git -c gpg.ssh.allowedSignersFile=.github/allowed_signers verify-tag v6.3.1 (https://github.com/Progressiverobot/hmailserver/blob/master/.github/SECURITY.md, 'Supply chain').


  • Other security issues


    Enough for a badge!

    The project results MUST check all inputs from potentially untrusted sources to ensure they are valid (an *allowlist*), and reject invalid inputs, if there are any restrictions on the data at all. [input_validation]
    Note that comparing input against a list of "bad formats" (aka a *denylist*) is normally not enough, because attackers can often work around a denylist. In particular, numbers are converted into internal formats and then checked if they are between their minimum and maximum (inclusive), and text strings are checked to ensure that they are valid text patterns (e.g., valid UTF-8, length, syntax, etc.). Some data may need to be "anything at all" (e.g., a file uploader), but these would typically be rare.

    The server is a network-facing protocol implementation and validates untrusted input at the boundary. SMTP, IMAP and POP3 command parsing accepts only the grammar each command defines and rejects the rest; line-terminator handling is deliberately restrictive, with the bare-LF SMTP-smuggling rule (CVE-2023-51764) enforced and pinned by its own test; SQL is exclusively parameterised by project rule, so message and header content is never concatenated into a query; and inputs are additionally exercised by a libFuzzer harness suite under fuzz/. See https://github.com/Progressiverobot/hmailserver/tree/master/fuzz


    Enough for a badge!

    Hardening mechanisms SHOULD be used in the software produced by the project so that software defects are less likely to result in security vulnerabilities. [hardening]
    Hardening mechanisms may include HTTP headers like Content Security Policy (CSP), compiler flags to mitigate attacks (such as -fstack-protector), or compiler flags to eliminate undefined behavior. For our purposes least privilege is not considered a hardening mechanism (least privilege is important, but separate).

    The native binaries are built with the MSVC hardening defaults left in place rather than disabled: /GS buffer security checks, DEP (/NXCOMPAT) and ASLR (/DYNAMICBASE) are all active for the x64 Release configuration. Control Flow Guard is not currently enabled and is a candidate for a future build change. Beyond compiler hardening, the server refuses unsafe password-hash schemes for new secrets and verifies TLS peers by default. See https://github.com/Progressiverobot/hmailserver/blob/master/hmailserver/source/Server/hMailServer/hMailServer.vcxproj


    Enough for a badge!

    The project MUST provide an assurance case that justifies why its security requirements are met. The assurance case MUST include: a description of the threat model, clear identification of trust boundaries, an argument that secure design principles have been applied, and an argument that common implementation security weaknesses have been countered. (URL required) [assurance_case]
    An assurance case is "a documented body of evidence that provides a convincing and valid argument that a specified set of critical claims regarding a system’s properties are adequately justified for a given application in a given environment" ("Software Assurance Using Structured Assurance Case Models", Thomas Rhodes et al, NIST Interagency Report 7608). Trust boundaries are boundaries where data or execution changes its level of trust, e.g., a server's boundaries in a typical web application. It's common to list secure design principles (such as Saltzer and Schroeer) and common implementation security weaknesses (such as the OWASP top 10 or CWE/SANS top 25), and show how each are countered. The BadgeApp assurance case may be a useful example. This is related to documentation_security, documentation_architecture, and implement_secure_design.

    ASSURANCE-CASE.md provides the assurance case: the security requirements as seven explicit claims (C1-C7); a threat model with actors A1-A6, assets and the principal attack surfaces; the trust boundaries B1-B6 with a diagram; the argument that secure design principles are applied (single management seam, complete mediation, fail-safe defaults, least privilege with a declared administrative boundary, defence in depth, separation of secrets, crypto agility); the argument that common implementation weaknesses are countered, mapped to CWE classes with the specific mechanisms; an evidence table per claim; and a plainly-stated residual-risk list. See https://github.com/Progressiverobot/hmailserver/blob/master/ASSURANCE-CASE.md


 Analysis 2/2 ●

  • Static code analysis


    Enough for a badge!

    The project MUST use at least one static analysis tool with rules or approaches to look for common vulnerabilities in the analyzed language or environment, if there is at least one FLOSS tool that can implement this criterion in the selected language. [static_analysis_common_vulnerabilities]
    Static analysis tools that are specifically designed to look for common vulnerabilities are more likely to find them. That said, using any static tools will typically help find some problems, so we are suggesting but not requiring this for the 'passing' level badge.

    CodeQL checks for common vulnerabilities including buffer overflows, use-after-free, and SQL injection. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/codeql.yml


  • Dynamic code analysis


    Enough for a badge!

    If the software produced by the project includes software written using a memory-unsafe language (e.g., C or C++), then at least one dynamic tool (e.g., a fuzzer or web application scanner) MUST be routinely used in combination with a mechanism to detect memory safety problems such as buffer overwrites. If the project does not produce software written in a memory-unsafe language, choose "not applicable" (N/A). [dynamic_analysis_unsafe]
    Examples of mechanisms to detect memory safety problems include Address Sanitizer (ASAN) (available in GCC and LLVM), Memory Sanitizer, and valgrind. Other potentially-used tools include thread sanitizer and undefined behavior sanitizer. Widespread assertions would also work.

    The regression test suite covers unsafe operations including TLS handshakes, authentication, and protocol parsing. See https://github.com/Progressiverobot/hmailserver/blob/master/README.md



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Project badge entry owned by: Progressive Robot.
Entry created on 2026-08-21 05:37:27 UTC, last updated on 2026-09-12 02:50:23 UTC. Last achieved passing badge on 2026-08-21 17:17:16 UTC.