Freedom251 › Mail Server Software
hMailServer
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| hMailServer | Free and open source under AGPL-3.0 · no per-mailbox fees · no paid tiers | Free |
As hmailserver.com lists them, read 12 Oct 2026. The maker's own page has the final word.
Facts from hMailServer's own pages
- Databases
- Windows supports SQL Server Compact, MySQL or MariaDB, Microsoft SQL Server and PostgreSQL; Linux supports PostgreSQL and MySQL or MariaDB. · hmailserver.co.uk, 12 Oct 2026
- Directories and calendars
- It serves account address books over CardDAV and calendars over CalDAV when the web services HTTPS listener is enabled. · hmailserver.co.uk, 12 Oct 2026
- Download verification
- The FAQ says release files have Sigstore bundles, Linux SHA-256 checksums and Windows Authenticode signature verification instructions. · hmailserver.co.uk, 12 Oct 2026
- Email authentication
- It supports SPF, DKIM, DMARC, MTA-STS, DANE, ARC sealing and TLS reporting. · hmailserver.co.uk, 12 Oct 2026
- Intended users
- The documentation suggests hMailServer for small businesses, developers needing an SMTP and IMAP test endpoint, and hosting providers. · hmailserver.co.uk, 12 Oct 2026
- Linux limitations
- Linux has no Control Panel, COM API or Microsoft SQL Server support, and moving an existing Windows installation to Linux is not a supported migration. · hmailserver.co.uk, 12 Oct 2026
- Mail protocols
- It serves mail to clients such as Outlook, Thunderbird and Apple Mail, or through its built-in webmail. · hmailserver.co.uk, 12 Oct 2026
- Not an Exchange replacement
- The FAQ says hMailServer has no Teams integration or ActiveSync and is not a replacement for Microsoft Exchange. · hmailserver.co.uk, 12 Oct 2026
- Purpose
- hMailServer is a self-hosted mail server that supports SMTP, IMAP and POP3. · gitlab.com, 12 Oct 2026
- REST API
- The REST API is available on Windows and Linux but is off by default; it requires a TLS certificate and key to bind beyond loopback. · hmailserver.co.uk, 12 Oct 2026
- Security updates
- The FAQ says release 6.3.6 fixes security flaws found in earlier versions and that the 6.3 line receives security fixes until 30 September 2027. · hmailserver.co.uk, 12 Oct 2026
- Spam and virus filtering
- It provides spam filtering, virus scanning through ClamAV, a rules engine and Sieve filtering. · hmailserver.co.uk, 12 Oct 2026
- Support
- Free help is available on the community forum, where answers are not gated behind a support plan. · hmailserver.co.uk, 12 Oct 2026
- Webmail
- It includes built-in webmail at `/portal` on Windows and Linux, enabled through the REST API listener. · hmailserver.co.uk, 12 Oct 2026
Where hMailServer stands on Freedom251
- Mail Server Software#5 of 34