hMailServer

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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.

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These are the Baseline Level 2 criteria. These are criteria version v2026.08.28.

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

        

 Basics

  • General

    Note that other projects may use the same name.

    hMailServer is a free, open-source mail server for Windows and Linux, implementing SMTP, IMAP and POP3, with webmail, a REST API and a Control Panel. It is a maintained fork of Martin Knafve's hMailServer, 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.

    This entry replaces https://www.bestpractices.dev/en/projects/14187, which was made through a GitHub login. GitHub suspended the project account on 18 September 2026, so that entry can no longer be edited. The project has lived on GitLab since 22 September 2026: https://gitlab.com/Progressiverobot/hmailserver. Every answer here was checked again against the project on 26 September 2026.

 Controls 16/19 ●

  • Controls


    Enough for a badge!

    When a CI/CD task is executed with no permissions specified, the CI/CD system MUST default the task's permissions to the lowest permissions granted in the pipeline. [OSPS-AC-04.01]
    Configure the project's settings to assign the lowest available permissions to new pipelines by default, granting additional permissions only when necessary for specific tasks.

    A GitLab CI job that declares nothing gets only its own CI_JOB_TOKEN, which works on a limited set of API endpoints. The project refuses job-token pushes to the repository, and its inbound job-token allowlist holds only the project itself. A job gets no OIDC ID token unless it declares one. The five project CI/CD variables are Azure identifiers, not secrets, and all are protected. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/.gitlab-ci.yml


    Enough for a badge!

    When an official release is created, that release MUST be assigned a unique version identifier. [OSPS-BR-02.01]
    Assign a unique version identifier to each release produced by the project, following a consistent naming convention or numbering scheme. Examples include SemVer, CalVer, or git commit id.

    Every release has a unique SemVer tag (v6.3.0 to v6.3.3 on GitLab, with earlier releases re-published under their original tags). Tags are annotated and SSH-signed from v6.2.23-alpha2 on, and the v* tag pattern is protected. See https://gitlab.com/Progressiverobot/hmailserver/-/releases


    Enough for a badge!

    When an official release is created, that release MUST contain a descriptive log of functional and security modifications. [OSPS-BR-04.01]
    Ensure that all releases include a descriptive change log. It is recommended to ensure that the change log is human-readable and includes details beyond commit messages, such as descriptions of the security impact or relevance to different use cases. To ensure machine readability, place the content under a markdown header such as "## Changelog".

    Every release on GitLab carries human-written notes on functional and security changes (6.3.3's run to about 25 KB), and CHANGELOG.md keeps the same log per version, including the 6.3.4 section. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CHANGELOG.md


    Enough for a badge!

    When a build and release pipeline ingests dependencies, it MUST use standardized tooling where available. [OSPS-BR-05.01]
    Use a common tooling for your ecosystem, such as package managers or dependency management tools to ingest dependencies at build time. This may include using a dependency file, lock file, or manifest to specify the required dependencies, which are then pulled in by the build system.

    The .NET projects use NuGet with committed lock files, restored with --locked-mode. The Linux build takes its libraries from the distribution's packages, in a CI image built from build/ci/linux.Dockerfile. OpenSSL, Boost and libpq are built from source archives at pinned versions, each checked against its SHA-256 (libraries/build-*.ps1), and every fetched binary input is pinned by hash in hmailserver/docs/third-party-binaries.json. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md


    Enough for a badge!

    When an official release is created, that release MUST be signed or accounted for in a signed manifest including each asset's cryptographic hashes. [OSPS-BR-06.01]
    Sign all released software assets at build time with a cryptographic signature or attestations, such as GPG or PGP signature, Sigstore signatures, SLSA provenance, or SLSA VSAs. Include the cryptographic hashes of each asset in a signed manifest or metadata file.

    Every asset of the releases from 6.2.19 to 6.3.3 carries its own keyless Sigstore bundle, and the Windows installer is Authenticode-signed since 6.3.1. From 6.3.4 every release also carries a SHA256SUMS manifest with each asset's SHA-256, signed with the release-tag SSH key listed in the repository's allowed_signers file (ssh-keygen -Y sign; checked with ssh-keygen -Y verify). How to verify each: https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md#verifying-a-release


    Enough for a badge!

    When the project has made a release, the project documentation MUST include a description of how the project selects, obtains, and tracks its dependencies. [OSPS-DO-06.01]
    It is recommended to publish this information alongside the project's technical & design documentation on a publicly viewable resource such as the source code repository, project website, or other channel.

    Several documents describe how dependencies are chosen, obtained and tracked. hmailserver/docs/ThirdPartyBinaries.md records each third-party build input: what it is, where it comes from, how the build fetches and hash-checks it, and why it is needed. SECURITY.md, "Supply chain" and "Dependencies", covers the pinned native libraries, the NuGet lock files, the dependency-scan job (Trivy and OSV) and Renovate (renovate.json). CONTRIBUTING.md lists the prerequisites. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/hmailserver/docs/ThirdPartyBinaries.md


    Enough for a badge!

    The project documentation MUST include instructions on how to build the software, including required libraries, frameworks, SDKs, and dependencies. [OSPS-DO-07.01]
    It is recommended to publish this information alongside the project's contributor documentation, such as in CONTRIBUTING.md or other developer task documentation. This may also be documented using Makefile targets or other automation scripts.

    README.md, "Building hMailServer", and CONTRIBUTING.md, "Prerequisites" and "Building", give the toolchain (Visual Studio 2026 / v145, Inno Setup, Perl, Python; clang and CMake on Linux). They say how to build OpenSSL, Boost and libpq, and how to get the hash-checked build inputs, with the build scripts under build/. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CONTRIBUTING.md#building


    Enough for a badge!

    The project documentation MUST include a list of project members with access to sensitive resources. [OSPS-GV-01.01]
    Document project participants and their roles through such artifacts as members.md, governance.md, maintainers.md, or similar file within the source code repository of the project. This may be as simple as including names or account handles in a list of maintainers, or more complex depending on the project's governance.

    GOVERNANCE.md, 'Maintainers', names the project's two maintainers and their accounts: Christopher Holloway (Progressiverobot on GitLab, the Owner; chrisholloway5 on GitHub) and Zain Ul Abidin (Zainulabidin90 on GitHub; zainulabidin1990 on GitLab from the next batch). A table shows which duties each holds, and 'Critical assets' lists the credentials. GitLab's member list shows the three accounts and their roles. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/GOVERNANCE.md#maintainers


    Enough for a badge!

    The project documentation MUST include descriptions of the roles and responsibilities for members of the project [OSPS-GV-01.02]
    Document project participants and their roles through such artifacts as members.md, governance.md, maintainers.md, or similar file within the source code repository of the project.

    GOVERNANCE.md describes the Maintainer, Contributor and Reporter roles and each one's responsibilities (accepting changes, releasing, security response, direction, infrastructure). It also has a table of which maintainer holds which duty today. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/GOVERNANCE.md#roles-and-responsibilities


    Enough for a badge!

    The project documentation MUST include a guide for code contributors that includes requirements for acceptable contributions. [OSPS-GV-03.02]
    Extend the CONTRIBUTING.md or CONTRIBUTING/ contents in the project documentation to outline the requirements for acceptable contributions, including coding standards, testing requirements, and submission guidelines for code contributors. It is recommended that this guide is the source of truth for both contributors and approvers.

    CONTRIBUTING.md sets the requirements for an acceptable contribution: one logical change, regression tests for behaviour changes, a warning-free build, parameterised SQL only, and settings in the database. It also covers the checkers to run, code style and licence headers, the change checklists (schema, COM, REST, UI), commit rules and DCO sign-off. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CONTRIBUTING.md


    Not enough for a badge.

    The version control system MUST require all code contributors to assert that they are legally authorized to make the associated contributions on every commit. [OSPS-LE-01.01]
    Include a DCO in the project's repository, requiring code contributors to assert that they are legally authorized to commit the associated contributions on every commit. Use a status check to ensure the assertion is made. A CLA also satisfies this requirement. Some version control systems, such as GitHub, may include this in the platform terms of service.

    CONTRIBUTING.md requires a DCO Signed-off-by, naming the commit's author, on every commit of a merge request from a fork. The sign-off job in .gitlab-ci.yml checks it, but no merge request has run it yet. The maintainers' own commits, which are almost all of master, are exempt and carry no sign-off, so not every commit carries the assertion. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CONTRIBUTING.md#sign-off


    Not enough for a badge.

    When a commit is made to the primary branch, any automated status checks for commits MUST pass or be manually bypassed. [OSPS-QA-03.01]
    Configure the project's version control system to require that all automated status checks pass or require manual acknowledgement before a commit can be merged into the primary branch. It is recommended that any optional status checks are NOT configured as a pass or fail requirement that approvers may be tempted to bypass.

    master is protected (only Maintainers push, no force-push) and GitLab's 'pipelines must succeed' setting is on for merge requests, but changes reach master by the maintainer's fast-forward push, which no status check gates: .gitlab-ci.yml defines the checks, but no full pipeline has run on GitLab yet. Every change is landed only after the maintainer's own full regression gate, the whole Windows suite split across two machines plus the whole Linux suite. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/hmailserver/docs/ContinuousIntegration.md


    Not enough for a badge.

    Prior to a commit being accepted, the project's CI/CD pipelines MUST run at least one automated test suite to ensure the changes meet expectations. [OSPS-QA-06.01]
    Automated tests should be run prior to every merge into the primary branch. The test suite should be run in a CI/CD pipeline and the results should be visible to all contributors. The test suite should be run in a consistent environment and should be run in a way that allows contributors to run the tests locally. Examples of test suites include unit tests, integration tests, and end-to-end tests.

    No CI/CD pipeline tests a change before it is accepted yet. .gitlab-ci.yml defines the whole Windows suite (windows-gate), the whole Linux suite (linux-suite) and the .NET tests on the project's own runners for master, batch* and v* pipelines, but no pipeline running them has run on GitLab (every push pipeline so far was skipped). Today every change is landed only after the maintainer's own full regression gate: the whole Windows suite split across two machines, plus the whole Linux suite. GitHub Actions ran the CI tests until 18 September 2026. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/hmailserver/docs/ContinuousIntegration.md


    Enough for a badge!

    When the project has made a release, the project documentation MUST include design documentation demonstrating all actions and actors within the system. [OSPS-SA-01.01]
    Include designs in the project documentation that explains the actions and actors. Actors include any subsystem or entity that can influence another segment in the system. Ensure this is updated for new features or breaking changes.

    ARCHITECTURE.md is the design document: the server's modules (SMTP, IMAP, POP3, the delivery queue, anti-spam and anti-virus, persistence over four database backends), the COM API as the management seam, the REST, metrics, web-services and ManageSieve listeners, scheduled work, the Linux build and the tests. ASSURANCE-CASE.md adds the actors (A1-A6) and the trust boundaries between them (B1-B6). https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/ARCHITECTURE.md


    Enough for a badge!

    When the project has made a release, the project documentation MUST include descriptions of all external software interfaces of the released software assets. [OSPS-SA-02.01]
    Document all software interfaces (APIs) of the released software assets, explaining how users can interact with the software and what data is expected or produced. Ensure this is updated for new features or breaking changes.

    README.md's Capabilities and Administration sections describe every external interface: SMTP, IMAP and POP3 with their extensions, ManageSieve, CardDAV and CalDAV, the REST API (which serves its own OpenAPI document at /api/v1/openapi.json), the Control Deck and webmail, Prometheus /metrics and health probes, OTLP export, SNMP and the COM API, with a document per feature under hmailserver/docs. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/README.md


    Enough for a badge!

    When the project has made a release, the project MUST perform a security assessment to understand the most likely and impactful potential security problems that could occur within the software. [OSPS-SA-03.01]
    Performing a security assessment informs both project members as well as downstream consumers that the project understands what problems could arise within the software. Understanding what threats could be realized helps the project manage and address risk. This information is useful to downstream consumers to demonstrate the security acumen and practices of the project. Ensure this is updated for new features or breaking changes.

    ASSURANCE-CASE.md is the project's security assessment: security claims C1-C7 argued with evidence, the threat model and trust boundaries, a CWE-by-CWE argument of how common weaknesses are countered, and the residual risk, with a status note on which checks ran on GitHub and what replaces them on GitLab. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/ASSURANCE-CASE.md


    Enough for a badge!

    The project documentation MUST include a policy for coordinated vulnerability disclosure (CVD), with a clear timeframe for response. [OSPS-VM-01.01]
    Create a SECURITY.md file at the root of the directory, outlining the project's policy for coordinated vulnerability disclosure. Include a method for reporting vulnerabilities. Set expectations for how the project will respond and address reported issues.

    SECURITY.md is the coordinated vulnerability disclosure policy: report privately by confidential GitLab issue or Service Desk email; acknowledgement within 5 working days, initial assessment within 10, a fix within 90 days of acknowledgement, and publication when the fix ships or at 90 days, whichever comes first. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md


    Enough for a badge!

    The project documentation MUST provide a means for private vulnerability reporting directly to the security contacts within the project. [OSPS-VM-03.01]
    Provide a means for security researchers to report vulnerabilities privately to the project. This may be a dedicated email address, a web form, VCS specialized tools, email addresses for security contacts, or other methods.

    SECURITY.md gives two private routes straight to the maintainers: a confidential GitLab issue with the Security template, visible only to the reporter and the project's members, or email to the Service Desk address contact-project+progressiverobot-hmailserver-86730559-issue-@incoming.gitlab.com, which GitLab files as a confidential issue, so no account is needed. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md#reporting-a-vulnerability


    Enough for a badge!

    The project documentation MUST publicly publish data about discovered vulnerabilities. [OSPS-VM-04.01]
    Provide information about known vulnerabilities in a predictable public channel, such as a CVE entry, blog post, or other medium. To the degree possible, this information should include affected version(s), how a consumer can determine if they are vulnerable, and instructions for mitigation or remediation.

    SECURITY.md: when a fix ships, the release notes describe the vulnerability, the confidential issue is made public, and a CVE ID requested through GitLab (a CNA) is quoted. The first vulnerability found in this fork, the JScript event-script injection fixed in 6.3.4, is described in CHANGELOG.md on master with the affected versions (6.0.0 to 6.3.3), the configurations exposed and the fix. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CHANGELOG.md



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Project badge entry owned by: christopher holloway.
Entry created on 2026-09-26 05:28:20 UTC, last updated on 2026-09-26 06:16:51 UTC. Last achieved passing badge on 2026-09-26 05:45:21 UTC.