hMailServer
hMailServer: A free, open-source Windows mail server for administrators who want control over email infrastructure. Ranked #119 of 178 in Email Hosting by our editors (5.3/10); pricing: Free plan; best for windows administrators building a mail server.
At a glance
- Editor score5.3 / 10
- PricingFree plan
- Best forWindows administrators building a mail server
- Free planYes
- Paid fromNone
- Facts checked22 Sep 2026
Where it wins
- SMTP, IMAP, POP3, DKIM, filtering, and outbound mail delivery
- ClamAV integration plus SPF, SURBL, DNS blacklist, and greylisting
- Aliases, fetching, APIs, migration tools, and multiple database options
Where it doesn't
- Windows-only server deployment limits platform flexibility
- Requires administrators to operate and maintain the mail infrastructure
- Does not provide verified webmail, mobile coverage, or calendar features
Our verdict on hMailServer
hMailServer is a free, open-source email server for organizations and administrators that want to operate their own mail infrastructure on Microsoft Windows. It runs as a Windows service and provides SMTP, IMAP, and POP3, with configurable domain and mailbox management. The feature set suits teams that need direct control over mail delivery, storage, filtering, and server administration rather than a hosted email service.
The product covers core mail-server operations in considerable detail. IMAP includes IDLE, SORT, Quota, and ACL extensions, while DKIM signing and verification support domain authentication. Filtering options include SPF, SURBL, DNS blacklists, greylisting, and score-based rules. Administrators can add ClamAV or a custom antivirus scanner, manage aliases, distribution lists, forwarding, and rules, and fetch messages from external POP3 accounts. MySQL, Microsoft SQL Server, and SQLite are supported, and the COM public API provides an automation path alongside the administrator GUI.
Its main trade-off is operational responsibility. hMailServer is built for a Windows deployment, so organizations choosing it should have administrators who can manage the server, databases, mail flow, filtering, and antivirus integrations. Storage, alias, and message-size limits are configurable, rather than organized as standard hosted-service allowances. The product also focuses on mail-server infrastructure: webmail, mobile access, and calendar functionality are not part of the documented feature set. Choose hMailServer when self-hosting, Windows administration, and configurable mail services are priorities; choose a hosted email product when browser, mobile, and broader collaboration access matter more.
Your product? Our editors can test hMailServer in depth and publish a review, labelled as paid · from $99/mo →
hMailServer pricing
hMailServer fact sheet
| Free plan | Yes |
|---|---|
| Paid from | None |
| Storage per mailbox | Not verified |
| Email aliases | Not verified |
| Attachment limit | Not verified |
| IMAP/POP support | Yes |
| Mobile app access | Not verified |
| Calendar included | Not verified |
| Migration tools | Yes |
| Deployment | Self-hosted |
| Platforms | Windows |
| Support | Docs, Community |
| Built for | Small business, Mid-market (editorial estimate) |
| Integrations | 4 integrations: MySQL, Microsoft SQL Server, SQLite, ClamAV |
| Pricing | Free plan |
| Website | hmailserver.com |
| Facts checked | 22 Sep 2026 |
hMailServer integrations
hMailServer lists 4 integrations on its own site.
- MySQL
- Microsoft SQL Server
- SQLite
- ClamAV
Alternatives to hMailServer
- Zoho MailA flexible business email suite with a free plan, low-cost entry tier, and migration support.9.4
- Microsoft Exchange OnlineA deep Exchange service for organizations centered on Outlook and administration.9.2
- Google WorkspaceA full Gmail-based collaboration suite for organizations that need more than email.9.1
See all hMailServer alternatives →
Also Ranked In
hMailServer is ranked in 2 of our directories.
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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