DBMail is an open-source project that enables storage of mail messages in a relational database.

Currently MySQL, PostgreSQL and SQLite can be used as storage backends.

Commercial development and support is also available.

What are the advantages?

Scalability
Dbmail is as scalable as the database system used for storage.
Manageability
Dbmail can be managed by updating the relational database or directory service - without shell access.
Speed
Dbmail uses very efficient, database specific queries for retrieving mail information.
Security
Dbmail doesn't require filesystem access. It's as secure as the database and directory server used.
Flexibility.
Changes in a Dbmail system (adding of users, changing passwords etc.) are effective immediately. Users can be stored in the database, or managed separately in an LDAP server such as OpenLDAP or Active Directory.

How does it work?

DBMail is made up of several components. A normal MTA (Postfix, SendMail, QMail, Exim) is used for accepting messages. The MTA hands the messages over to dbmail-deliver, using a pipe interface, or to dbmail-lmtpd, using LMTP (Local Mail Transport Protocol).

These programs take care of injecting the message into the database. Messages can be retreived from the database using dbmail-pop3d, using the POP3 protocol, or dbmail-imapd, using the IMAP4Rev1 protocol.

Emails are stored in the database. This includes attachments. User information is also stored in the database, so users do not need a system account on machines DBMail is running on.

Components

DBMail Components

Available

DBMail is primarily developed and tested on the GNU Linux and FreeBSD platforms. Users have also reported successfull deployments on OpenSolaris, NetBSD and OSX.

DBMail is released under the GNU Public Licence (version 2).

News

DBMail 2.2.15 released
2010-02-13
DBMail 2.2.14 released
2010-01-22
DBMail 2.2.12 released
2009-10-07

Blog

Pruning the dbmail_headervalue table
2010-02-13
DBMail on twitter
2010-01-19
re-theming dbmail.org
2010-01-07

Recent changes

master branch

[wip] reduce data races
2010-03-08
fix small pop3 error
2010-03-08
make cidr type opaque
2010-02-13

stable branch

tag and bump version 2.2.15
2010-02-13
stress-testing lmtp
2010-02-02
defensive cleanups
2010-01-26