Perdition: Mail Retrieval Proxy v1.19-rc2
Perdition is a fully featured POP3, IMAP4 and ManageSieve proxy server. It is able to handle both SSL and non-SSL connections and redirect users to a real-server based on a database lookup. Perdition supports modular based database access. ODBC, MySQL, PostgreSQL, GDBM, POSIX Regular Expression and NIS modules ship with the distribution. The API for modules is open allowing arbitrary modules to be written to allow access to any data store.
Perdition has many uses. Including, creating large mail systems where an end-user's mailbox may be stored on one of several hosts, integrating different mail systems together, migrating between different email infrastructures, and bridging plain-text, SSL and TLS services. It can also be used as part of a firewall.