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 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.

 Controls 18/19 ●

  • 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.

    The repository's GitHub Actions default workflow token permission is read-only (verified via API: gh api repos/Progressiverobot/hmailserver/actions/permissions/workflow returns default_workflow_permissions=read), so any CI/CD task with no permissions specified receives a read-only GITHUB_TOKEN — the lowest default. In addition, all 10 workflows on master declare an explicit top-level permissions block: nine are read-only or empty (contents: read; contents: read + actions: read; read-all; {}), and upstream-watch.yml adds issues: write at workflow level, needed by its single job to file upstream-tracking issues. Other write scopes are granted per job only where required: id-token: write and contents: write in sign-release.yml's signing job (keyless cosign signing and asset upload), security-events: write for CodeQL and Scorecard SARIF upload (Scorecard also id-token: write), contents: write in the SBOM job to attach release assets, and pull-requests: write in dependency-review. See https://github.com/Progressiverobot/hmailserver/tree/master/.github/workflows


    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 is assigned a unique SemVer-style tag: v6.2.2 through v6.2.21 for stable releases, with pre-releases distinguished by suffix (v6.2.22-pre1..pre6, v6.2.23-alpha1). 25+ releases enumerated via the GitHub API each carry a distinct tag_name, and an active 'Protect release tags' ruleset protects the tags after publication. See https://github.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".

    Each GitHub Release carries thorough, human-written notes describing functional and security modifications. v6.2.21's body is ~11.8 KB; v6.2.23-alpha1's notes describe new features, breaking changes (database schema 6022->6025), security-relevant fixes (a path silently losing mail, a COM vtable compatibility break, an installer hang), and upgrade cautions with backup instructions. Release notes name CVEs where relevant (e.g. the CVE-2023-51764 SMTP-smuggling rule). The notes are not placed under a literal '## Changelog' header, which the criterion recommends but does not require. See https://github.com/Progressiverobot/hmailserver/releases


    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.

    .NET dependencies are ingested with standard tooling: CI runs 'dotnet restore' (NuGet) on ControlPanel.csproj and the Tools solution (ci.yml), and Dependabot manages the nuget and github-actions ecosystems weekly (.github/dependabot.yml); GitHub Actions are pinned by commit SHA. The native C++ dependencies (OpenSSL, Boost, libpq) have no ecosystem package manager in this project's MSVC flow — they are built from pinned source versions per documented steps under %hMailServerLibs% — and every binary committed to the tree is SHA-256-inventoried in hmailserver/docs/third-party-binaries.json, enforced by the verify-binary-provenance workflow. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/dependabot.yml


    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.

    Since v6.2.19, every release asset is signed at release time with Sigstore cosign (keyless): sign-release.yml runs 'cosign sign-blob --bundle' over each release asset, verifies each bundle with 'cosign verify-blob' pinning the signing workflow identity before upload, and attaches a .cosign.bundle per asset. The latest stable release v6.2.21 and latest prerelease v6.2.23-alpha1 each ship the installer plus SPDX and CycloneDX SBOMs, each asset with its own .cosign.bundle. User-facing verification commands are documented in the workflow header. Releases prior to v6.2.19 predate the signing process and are unsigned. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/sign-release.yml


    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.

    Dependency handling is documented publicly: README's third-party libraries section explains how OpenSSL 4.0.x, Boost 1.91 and PostgreSQL 18 libpq are obtained and built at pinned versions under %hMailServerLibs%; .github/dependabot.yml states the tracking policy (NuGet and GitHub Actions updated weekly via Dependabot; native C++ libs tracked manually since Dependabot has no C++ ecosystem); and hmailserver/docs/ThirdPartyBinaries.md records, for each of the 40 committed binaries, what it is, where it came from, why it is present and whether it should be, with SHA-256s in third-party-binaries.json enforced by CI. SBOMs ship with each release. See https://github.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 has a contents-linked 'Building hMailServer' section covering prerequisites (Visual Studio 2026 / v145 toolset with the required workloads, Inno Setup 6, Perl, Python), step-by-step instructions for building the external libraries (OpenSSL via nmake, PostgreSQL libpq via meson, Boost via b2) under %hMailServerLibs%, and building the server, tools and installer via the build*.ps1 scripts or MSBuild, including a warning about build events on machines running a production instance. .github/CONTRIBUTING.md summarizes the same and points back to the README. See https://github.com/Progressiverobot/hmailserver/blob/master/README.md#building-hmailserver


    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.

    The project has exactly one member with access to sensitive resources, and he is documented by name and handle on master: README states the fork 'is maintained by Christopher Holloway / Progressive Robot Ltd'; .github/CODEOWNERS lists @chrisholloway5 as owner of every path, explicitly enumerating the sensitive ones (CI workflows, release/signing files, committed third-party binaries, TLS/crypto code); SECURITY.md states it is a single-maintainer project. PR #40's GOVERNANCE.md will restate this as a formal member list once merged. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CODEOWNERS


    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 documents the project roles and their responsibilities: the Maintainer role (accepting changes, releasing per RELEASE.md, security response per SECURITY.md, direction via Roadmap.md, custody of critical credentials), the Contributor role (expectations set by CONTRIBUTING.md), and the Reporter role (SUPPORT.md / SECURITY.md paths). Who currently holds each role is stated by name. See https://github.com/Progressiverobot/hmailserver/blob/master/GOVERNANCE.md


    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.

    .github/CONTRIBUTING.md on master sets requirements for acceptable contributions: coding standards (code must build warning-free under /WX; parameterised SQL exclusively, never manually built SQL strings; new optional server features follow the INI-settings pattern), testing requirements (all changes must keep the regression suite green; add or update regression tests for behavior changes), submission guidelines (branch from master, one logical change per PR), architectural guidance on the BO/Persistence/COM layering, and licensing terms (contributions licensed under AGPLv3). See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md


    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.

    There is no DCO status check or CLA. The repository is hosted on GitHub, and this criterion's guidance explicitly accepts the platform's terms of service: GitHub's Terms of Service (section D) require every user, on every contribution, to represent that they have the right to post the content, and license inbound contributions under the repository's license. All contributions arrive through GitHub (a sole maintainer plus Dependabot). CONTRIBUTING.md additionally states 'By contributing you agree that your contributions are licensed under the AGPLv3'. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/CONTRIBUTING.md


    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 has no branch protection (GitHub API returns 404 'Branch not protected') and no branch ruleset applies to it (rules/branches/master returns an empty list; the only active ruleset protects release tags). CI, CodeQL and dependency-review workflows run on pushes and PRs, but nothing requires their status checks to pass before a commit lands: the sole maintainer pushes directly to master as the normal workflow, so a failing check cannot block a change. Adding required status checks on master would close this gap. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/ci.yml


    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.

    The CI workflow (.github/workflows/ci.yml) triggers on every push and pull request to master and runs an automated test suite: 'dotnet test' on ControlPanel.Tests with cobertura coverage, plus a generated-code drift check and -warnaserror builds. Results are publicly visible in the Actions tab, and contributors can run the same tests locally (dotnet test; build/build-tests.ps1 and build/run-tests.ps1 are documented in CONTRIBUTING.md). Pull requests are tested before merge; every commit reaching master is tested by the same pipeline. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/workflows/ci.yml


    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 at the repo root is a maintained 218-line design document describing the system's components and how they interact: the C++ server modules (SMTP/IMAP/POP3, delivery queue, anti-spam/anti-virus, persistence layering BO->Persistence->SQL with caches over four database backends), the COM/IDispatch API as the management seam used by the Control Panel, the test suite and third-party scripts, the optional listeners (REST, metrics, web services, ManageSieve) with their threading and TLS behavior, the scheduler, and external actors such as ClamAV, SpamAssassin, DNS and the databases. It records interaction constraints and is kept current. See https://github.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 documents all external interfaces of the released software: SMTP, IMAP and POP3 with per-extension RFC citations; SASL mechanisms (SCRAM-SHA-256/-PLUS); Sieve plus the ManageSieve (RFC 5804) listener with its command set; the REST administration API with its complete endpoint list (/api/v1/status, domains, accounts, queue, apikeys, tlsa) and authentication model (administrator password or scoped API keys); the Prometheus /metrics endpoint with metric names and the /livez, /readyz, /healthz probes; OTLP trace/metrics/logs endpoints; the COM/IDispatch API; and the hMailServer.ini configuration surface. ARCHITECTURE.md describes the COM API's role as the management seam. See https://github.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 documented security assessment: a threat model with actors and principal attack surfaces, trust boundaries B1-B6, security claims C1-C7 argued with evidence, CWE-mapped analysis of how common implementation weaknesses are countered, and a residual-risk list. It is supported by continuous tooling on master: CodeQL on every push and pull request, OpenSSF Scorecard, and a libFuzzer harness suite under fuzz/. See https://github.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 (in .github/, shown on the repo's Security tab) is a full coordinated vulnerability disclosure policy with explicit timeframes: acknowledgement within 5 working days, initial assessment (reproduction or request for more information) within 10 working days, and a fix for a confirmed vulnerability within 90 days of acknowledgement. It commits to coordinated disclosure on a 90-day timetable (advisory published when the fix ships or at 90 days, whichever is first), asks reporters to flag earlier disclosure intentions, states the credit policy, and defines in-scope and out-of-scope report classes. Verified on master. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/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.

    Private vulnerability reporting is enabled on the repository (verified via the GitHub API), and SECURITY.md directs reporters to the private channel with a direct link to https://github.com/Progressiverobot/hmailserver/security/advisories/new, explicitly instructs against public issues, discussions, PRs or forum posts for security problems, and provides a fallback: a reporter who cannot use GitHub Security Advisories may open an issue containing no technical detail asking for a private channel, and the maintainer will open an advisory and invite them. Reports go directly to the maintainer, who is the security contact. See https://github.com/Progressiverobot/hmailserver/blob/master/.github/SECURITY.md


    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.

    The project publishes vulnerability data through GitHub Security Advisories and release notes. SECURITY.md commits that once a fix is available it ships as a new build and the advisory is published with a CVE requested through GitHub, on a 90-day coordinated-disclosure timetable. To date no vulnerability has been discovered in this fork, so the public advisory list is empty (verified via the GitHub API: zero published advisories, none withheld); where upstream CVEs are relevant the release notes name them explicitly (e.g. CVE-2023-51764 SMTP smuggling, whose mitigation is enforced and pinned by a regression test). See https://github.com/Progressiverobot/hmailserver/blob/master/.github/SECURITY.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.