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 3 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 17/21 ●

  • Controls


    Enough for a badge!

    When a job is assigned permissions in a CI/CD pipeline, the source code or configuration MUST only assign the minimum privileges necessary for the corresponding activity. [OSPS-AC-04.02]
    Configure the project's CI/CD pipelines to assign the lowest available permissions to users and services by default, elevating permissions only when necessary for specific tasks. In some version control systems, this may be possible at the organizational or repository level. If not, set permissions at the top level of the pipeline.

    The CI file on master grants no job an ID token or a secret. The release jobs in the next batch are the only ones that ask for an ID token: release-authenticode for audience api://AzureADTokenExchange, and release-sign for audience sigstore. Both run only for a protected v* tag, and the build/ci/repo-hygiene.py check fails any job that asks for id_tokens or secrets and can run for a merge request. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/.gitlab-ci.yml


    Enough for a badge!

    CI/CD pipelines which accept trusted collaborator input MUST sanitize and validate that input prior to use in the pipeline. [OSPS-BR-01.04]
    CI/CD pipelines should sanitize (quote, escape or exit on expected values) all collaborator inputs on explicit workflow executions. While collaborators are generally trusted, manual inputs to a workflow cannot be reviewed and could be abused by an account takeover or insider threat.

    GitLab pipelines here accept no collaborator input. The project's minimum role for pipeline variables is 'no one allowed', so nobody can pass variables when starting a pipeline, and .gitlab-ci.yml defines no spec:inputs. The manual jobs take no parameters, and what a schedule sets is only compared in rules. The GitHub workflow that interpolated a dispatch input (installer-smoke.yml) no longer runs and is removed in the next batch. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/.gitlab-ci.yml


    Enough for a badge!

    When an official release is created, all assets within that release MUST be clearly associated with the release identifier or another unique identifier for the asset. [OSPS-BR-02.02]
    Assign a unique version identifier to each software asset produced by the project, following a consistent naming convention or numbering scheme. Examples include SemVer, CalVer, or git commit id.

    Each release's files are in the package registry under the version, e.g. /packages/generic/hmailserver/6.3.3/, and are linked from the release with that tag. The installer and the packages also carry the version in their file names (hMailServer-6.3.3-x64.exe, hmailserver_6.3.3_amd64.deb). See https://gitlab.com/Progressiverobot/hmailserver/-/releases/v6.3.3


    Enough for a badge!

    The project MUST define a policy for managing secrets and credentials used by the project. The policy should include guidelines for storing, accessing, and rotating secrets and credentials. [OSPS-BR-07.02]
    Document how secrets and credentials are managed and used within the project. This should include details on how secrets are stored (e.g., using a secrets management tool), how access is controlled, and how secrets are rotated or updated. Ensure that sensitive information is not hard-coded in the source code or stored in version control systems.

    SECURITY.md, 'Secrets and credentials', is the policy. No token, password or signing key is committed, and the test keys are throwaway fixtures. Release-asset signing is keyless (Sigstore), and the tag-signing keys' public halves are in allowed_signers. A secret is rotated when a maintainer leaves, when its pipeline changes hands, on any suspicion of exposure, and before it expires. GOVERNANCE.md says only Christopher Holloway holds the credentials under 'Critical assets'. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md


    Enough for a badge!

    When the project has made a release, the project documentation MUST contain instructions to verify the integrity and authenticity of the release assets. [OSPS-DO-03.01]
    Instructions in the project should contain information about the technology used, the commands to run, and the expected output. When possible, avoid storing this documentation in the same location as the build and release pipeline to avoid a single breach compromising both the software and the documentation for verifying the integrity of the software.

    SECURITY.md, "Verifying a release", gives the commands. git verify-tag against the committed allowed signers file checks the tag. cosign verify-blob, with the bundle, certificate identity and OIDC issuer, checks each asset of the releases up to 6.3.3. Get-AuthenticodeSignature checks the Windows installer from 6.3.1. It also names the tool each check uses. See 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 contain instructions to verify the expected identity of the person or process authoring the software release. [OSPS-DO-03.02]
    The expected identity may be in the form of key IDs used to sign, issuer and identity from a sigstore certificate, or other similar forms. When possible, avoid storing this documentation in the same location as the build and release pipeline to avoid a single breach compromising both the software and the documentation for verifying the integrity of the software.

    SECURITY.md, 'Verifying a release', says release tags verify against the committed allowed_signers file, which holds one key, christopher.j.holloway@outlook.com's (.github/ on master, .gitlab/ from the next batch). Assets up to 6.3.3 must carry the Sigstore identity ^https://github.com/Progressiverobot/hmailserver/ with the issuer https://token.actions.githubusercontent.com. The next batch adds the GitLab identity and the issuer https://gitlab.com for releases from 6.3.5. See 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 descriptive statement about the scope and duration of support for each release. [OSPS-DO-04.01]
    In order to communicate the scope and duration of support for the project's released software assets, the project should have a SUPPORT.md file, a "Support" section in SECURITY.md, or other documentation explaining the support lifecycle, including the expected duration of support for each release, the types of support provided (e.g., bug fixes, security updates), and any relevant policies or procedures for obtaining support.

    SECURITY.md's "Supported versions" names the supported line (6.3.x) and says a fix ships in the next release, with no back-ports because there are no maintenance branches. SUPPORT.md describes the support offered: issues, the forum, what to expect, and no guaranteed response time. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md#supported-versions


    Enough for a badge!

    When the project has made a release, the project documentation MUST provide a descriptive statement when releases or versions will no longer receive security updates. [OSPS-DO-05.01]
    In order to communicate the scope and duration of support for security fixes, the project should have a SUPPORT.md or other documentation explaining the project's policy for security updates.

    SECURITY.md says only the 6.3 line receives security fixes and everything older than 6.3 does not. A fix ships in the next 6.3 release and is not back-ported, so a release stops receiving security updates once a newer one is published. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md#supported-versions


    Enough for a badge!

    The project documentation MUST have a policy that code collaborators are reviewed prior to granting escalated permissions to sensitive resources. [OSPS-GV-04.01]
    Publish an enforceable policy in the project documentation that requires code collaborators to be reviewed and approved before being granted escalated permissions to sensitive resources, such as merge approval or access to secrets. It is recommended that vetting includes establishing a justifiable lineage of identity such as confirming the contributor's association with a known trusted organization.

    GOVERNANCE.md, 'Becoming a maintainer', sets the rule for escalated access: a sustained record of correct, tested changes and willingness to take on the release and security duties, decided by the maintainers. It records openly that the second maintainer was appointed from within Progressive Robot Ltd before building that record. Only Progressiverobot, the project's one member above Developer, can grant a GitLab role. See https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/GOVERNANCE.md#becoming-a-maintainer


    Not enough for a badge.

    When the project has made a release, all compiled released software assets MUST be delivered with a software bill of materials. [OSPS-QA-02.02]
    It is recommended to auto-generate SBOMs at build time using a tool that has been vetted for accuracy. This enables users to ingest this data in a standardized approach alongside other projects in their environment.

    Every release from v6.2.3 on carries SPDX and CycloneDX SBOMs (hmailserver.spdx.json, hmailserver.cyclonedx.json) beside its installer and packages, but five earlier releases still listed (v6.0.0-B1, v6.0.0, v6.1.0, v6.2.1, v6.2.2) carry an installer with no SBOM. https://gitlab.com/Progressiverobot/hmailserver/-/releases


    Enough for a badge!

    When the project has made a release comprising multiple source code repositories, all subprojects MUST enforce security requirements that are as strict or stricter than the primary codebase. [OSPS-QA-04.02]
    Any additional subproject code repositories produced by the project and compiled into a release must enforce security requirements as applicable to the status and intent of the respective codebase. In addition to following the corresponding OSPS Baseline requirements, this may include requiring a security review, ensuring that it is free of vulnerabilities, and ensuring that it is free of known security issues.

    Releases are built from one repository alone: the server, the .NET tools, the web front ends and the vendored third-party code (inventoried in hmailserver/docs/third-party-binaries.json) all live there, so there are no subproject repositories to hold to the primary codebase's requirements. https://gitlab.com/Progressiverobot/hmailserver


    Enough for a badge!

    The project documentation MUST clearly document when and how tests are run. [OSPS-QA-06.02]
    Add a section to the contributing documentation that explains how to run the tests locally and how to run the tests in the CI/CD pipeline. The documentation should explain what the tests are testing and how to interpret the results.

    CONTRIBUTING.md's Testing section says how to run the Windows regression suite (the bench, build/preflight-tests.ps1, build/run-tests.ps1) and the Linux suite (dotnet test with the HMTEST_* settings), what they exercise and how to read the result; 'The checkers' and hmailserver/docs/ContinuousIntegration.md say which checks and suites each GitLab CI job runs, where, and for which refs. RELEASE.md requires the full suite, zero failures, on the exact binary that ships. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CONTRIBUTING.md#testing


    Enough for a badge!

    The project documentation MUST include a policy that all major changes to the software produced by the project should add or update tests of the functionality in an automated test suite. [OSPS-QA-06.03]
    Add a section to the contributing documentation that explains the policy for adding or updating tests. The policy should explain what constitutes a major change and what tests should be added or updated.

    CONTRIBUTING.md makes it policy: 'Add or update regression tests for a change of behaviour' (Merge requests), and 'A fix ships with a test that fails against the build before it' (Writing a test); RELEASE.md requires a negative-control test for every defect fix. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CONTRIBUTING.md#merge-requests


    Not enough for a badge.

    When a commit is made to the primary branch, the project's version control system MUST require at least one non-author human approval of the changes before merging. [OSPS-QA-07.01]
    Configure the project's version control system to require at least one non-author human approval of changes before merging into the release or primary branch. This can be achieved by requiring a pull request to be reviewed and approved by at least one other collaborator before it can be merged.

    No approval rule is configured on GitLab, so nothing requires a non-author human approval before a change reaches master; CONTRIBUTING.md says so. One active maintainer lands changes, each checked by adversarial review passes run by AI agents, fixture gates and the full regression gate before it lands, which is not two-person review. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/CONTRIBUTING.md#merge-requests


    Enough for a badge!

    When the project has made a release, the project MUST perform a threat modeling and attack surface analysis to understand and protect against attacks on critical code paths, functions, and interactions within the system. [OSPS-SA-03.02]
    Threat modeling is an activity where the project looks at the codebase, associated processes and infrastructure, interfaces, key components and "thinks like a hacker" and brainstorms how the system be be broken or compromised. Each identified threat is listed out so the project can then think about how to proactively avoid or close off any gaps/vulnerabilities that could arise. Ensure this is updated for new features or breaking changes.

    Sections 3 and 4 of ASSURANCE-CASE.md are the threat model and attack-surface analysis: actors A1-A6 with their assumed capabilities, the assets, the principal attack surfaces (protocol parsers, MIME parsing, TLS, the scanner and DNS paths, persistence, and the REST, metrics and web-services listeners) and trust boundaries B1-B6 with the check made at each. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/ASSURANCE-CASE.md#3-threat-model


    Enough for a badge!

    Any vulnerabilities in the software components not affecting the project MUST be accounted for in a VEX document, augmenting the vulnerability report with non-exploitability details. [OSPS-VM-04.02]
    Establish a VEX feed communicating the exploitability status of known vulnerabilities, including assessment details or any mitigations in place preventing vulnerable code from being executed.

    The project keeps an OpenVEX document, .github/hmailserver.openvex.json (moving to .gitlab/ with the next batch), with a not_affected statement and its justification for every advisory dismissed as not affecting the project: five today, for zlib and Boost advisories found by the dependency-scan OSV query. SECURITY.md requires a statement for each such dismissal, and the dependency-scan job honours the document. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/.github/hmailserver.openvex.json


    Enough for a badge!

    The project documentation MUST include a policy that defines a threshold for remediation of SCA findings related to vulnerabilities and licenses. [OSPS-VM-05.01]
    Document a policy in the project that defines a threshold for remediation of SCA findings related to vulnerabilities and licenses. Include the process for identifying, prioritizing, and remediating these findings.

    SECURITY.md's Vulnerability management policy sets the SCA thresholds: a high or critical advisory in a dependency is fixed, or the dependency replaced, before the next release and within 14 days; moderate within 30 days; low within 90 days or with the next refresh; a licence incompatible with AGPL-3.0-or-later is treated as high. It says how findings are found (the dependency-scan job's Trivy and OSV queries, Renovate) and how a not-affected one is recorded in the VEX document. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md#dependencies-software-composition-analysis


    Enough for a badge!

    The project documentation MUST include a policy to address SCA violations prior to any release. [OSPS-VM-05.02]
    Document a policy in the project to address applicable Software Composition Analysis results before any release, and add status checks that verify compliance with that policy prior to release.

    SECURITY.md: a release is not cut while a known high or critical advisory against a shipped dependency is open; the dependency-scan report of the release's commit is read first, and every component it marks UNKNOWN is checked by hand against the release's SBOM. That check is made by hand: the dependency-scan job is defined in .gitlab-ci.yml, not blocking, and has not yet run on GitLab. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md#dependencies-software-composition-analysis


    Not enough for a badge.

    All changes to the project's codebase MUST be automatically evaluated against a documented policy for malicious dependencies and known vulnerabilities in dependencies, then blocked in the event of violations, except when declared and suppressed as non-exploitable. [OSPS-VM-05.03]
    Create a status check in the project's version control system that runs a Software Composition Analysis tool on all changes to the codebase. Require that the status check passes before changes can be merged.

    Not every change is evaluated and blocked. The dependency-scan job (Trivy and OSV, honouring the VEX document) is defined for master, batch* and v* pipelines on the project's runner only, is allow_failure, and has not yet run on GitLab; merge requests do not reach it, and Renovate waits for the owner's token and schedule. GitHub's blocking dependency review ran until 18 September 2026. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/hmailserver/docs/ContinuousIntegration.md


    Enough for a badge!

    The project documentation MUST include a policy that defines a threshold for remediation of SAST findings. [OSPS-VM-06.01]
    Document a policy in the project that defines a threshold for remediation of Static Application Security Testing (SAST) findings. Include the process for identifying, prioritizing, and remediating these findings.

    SECURITY.md's Vulnerability management policy sets the SAST threshold: an error-level finding, or a high or critical security finding, is fixed before merge; medium within 30 days; low or note-level with the next change to that file or dismissed with a written reason; no release with an open error-level finding. It names the tools (cppcheck, clang-tidy and Semgrep in CI, MSVC /analyze by hand) and how suppressions are recorded. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/SECURITY.md#source-code-static-analysis


    Not enough for a badge.

    All changes to the project's codebase MUST be automatically evaluated against a documented policy for security weaknesses and blocked in the event of violations except when declared and suppressed as non-exploitable. [OSPS-VM-06.02]
    Create a status check in the project's version control system that runs a Static Application Security Testing (SAST) tool on all changes to the codebase. Require that the status check passes before changes can be merged.

    SAST does not yet block changes. The static-analysis (cppcheck, clang-tidy) and semgrep jobs are defined for master, batch* and v* pipelines only, are allow_failure against committed baselines until triaged, do not read the Windows-only sources, and have not yet run on GitLab; GitLab SAST and secret detection come with the next batch. CodeQL ran on GitHub until 18 September 2026. https://gitlab.com/Progressiverobot/hmailserver/-/blob/master/hmailserver/docs/ContinuousIntegration.md#security-scanning



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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.