DBMail - Storage of mails in a Database

Dbmail is as scalable as the database system used for storing mails and attachments. Currently MySQL, PostgreSQL and SQLite can be used as storage backends. A normal MTA (Postfix, SendMail, QMail, Exim) is used for accepting messages and forwards to DBMail which in turn stores it in database. Messages stored could be retrieved using POP3 and IMAP protocol.