Free and all you will need

hMailServer provides all of the important functionality you need
to run your own e-mail server. As a user of hMailServer, you get continuous updates
and great support from other users and developers in the forum.
hMailServer is a free product. Free when it comes to the price, and free
when it comes to how you can use or distribute it.
hMailServer supports the
open email standards POP3, SMTP and IMAP4. This
makes the server compatible with most email clients available. hMailServer 4 and
earlier versions are licensed as open source under the GPL license. Later versions
of hMailServer (version 5 and later) are still free of charge but closed source.
Installation & Configuration

Tired of manually editing .conf and .ini files? Installing and configuring hMailServer is
easy and takes only a few minutes. The server comes with an easy-to-use MMC-like administration called hMailAdmin. hMailAdmin lets
you add domains & accounts, specify settings, enable virus scanning and so on.
The documentation describes the features in detail. If you have any questions, there's
a great user forum full of helping users to turn to. The hMailServer developers answers
question in this forum as well. When you seek support at the forum, the average reply time is less than two hours!
Database support
hMailServer supports
Microsoft SQL Server,
PostgreSQL and
MySQL.
The hMailServer installation includes a minimal, built-in database server called Microsoft SQL Server Compact. During the installation
you can choose whether you want to use the built-in database or a already existing database server. The built-in server saves
you the hassle of having to set up and configure a separate database server for hMailServer, but using an external database server
may give better performance.
Webmail

hMailServer is compatible with any email client which supports SMTP, POP3 and IMAP. This is true also when it comes to web mail clients.
hMailServer can use any web mail system which supports these protocols (normally SMTP and IMAP is used, not POP3). Depending on what server you
are running, different web mail systems may suit your needs. For example, some webmail systems relies on the PHP scripting engine (which typically runs
under Apache) while other relies on ASP (which normally runs under Microsoft Internet Information servers).
Security

hMailServer is pre-configured to have high security when it comes to
relaying and authentication so that no one can use your server to send spam messages. It also supports the very popular open source
virus scanner ClamAV. Configuring hMailServer to use ClamAV only
takes a single click! The server also supports black list servers and other spam-stopping mechanisms such as SPF and MX lookups.
Integration

hMailServer comes with a COM library that can be used for integration with other software. Using the COM
library, it's possible to write scripts and full applications that utilize the features in hMailServer. For example, you can integrate hMailServer into
your current IT-systems so that new employees automatically get email accounts. Both hMailServer Administrator and the PHP web-based frontend uses the COM API
to manage the server.
Main features
- POP3, SMTP, IMAP
- Virtual domains
- Built-in backup
- SSL encryption
- Anti-spam
- Anti-virus
- Scripting
- Server-side rules
- Multilingual
- Routing
- MX backup
- Multihoming
- SQL backend
- Web administration
Integrations