As one of the few robust open-source mail servers natively running on Windows, hMailServer fills a critical niche for administrators familiar with the Windows environment who require a stable SMTP, POP3, and IMAP server.
: Scale to thousands of users without paying per-mailbox fees.
Several unpublished CVEs (Common Vulnerabilities and Exposures) have been addressed in the 5.7 codebase, particularly around SMTP command injection.
: Full native support for IMAP, SMTP, and POP3. download hmailserver 57 hot
[Settings] ThreadPoolSize=12 (CPU cores × 2 recommended) QueueCacheSize=524288000 (512MB)
Often found on development build sites (such as build.hmailserver.com), this 5.7 branch includes necessary patches for modernizing the server, offering better stability compared to the older, unpatched 5.6 versions. Key Features and Improvements in 5.7 Hotfix
Includes built-in mechanisms like ClamAV for virus scanning, SPF (Sender Policy Framework), DNS Blacklisting, and Greylisting to keep your inbox clean. As one of the few robust open-source mail
is the stable, feature-rich version that many continue to rely on. It provides all the functionality of expensive proprietary mail servers without the licensing costs.
hMailServer 5.6.8 - Build 2574 (Released March 2021)
hMailServer is a free, open-source e-mail server for Microsoft Windows. It is used by internet service providers, companies, governments, and schools worldwide. : Full native support for IMAP, SMTP, and POP3
: You will be prompted to create an administration password; keep this safe as it is required to manage the server. Basic Configuration Add Domain : Open the hMailServer Administrator, connect to , and add the domain you want to use (e.g., yourdomain.com Create Accounts
You can typically find official builds and source code through the project's repository on .
: Recommended for production (supports MySQL, MS SQL Server, and PostgreSQL). 4. Configuration