Courier-IMAP is an enterprise-grade IMAP server that is fast and scalable. It works with Maildirs to store and manage email messages efficiently.
In proxy mode, a pool of Courier servers receive IMAP and POP3 connections, establish a proxy connection to the actual server hosting the mail account, and wait for login requests from clients. However, please be aware that this IMAP server does not handle traditional mailbox files, as it is optimized for providing IMAP access to Maildirs.
Maildir is a directory-based mail storage format that works well over NFS without any locking-related issues. The primary advantage of maildirs is that multiple applications can access the same Maildir simultaneously without requiring any kind of locking whatsoever. Courier-IMAP is perfectly suited for Qmail, Exim, and Postfix sites that are configured for maildirs.
This software is the same IMAP server included in the Courier mail server but is configured as a standalone IMAP server that can be used with other mail servers, such as Qmail, Exim, or Postfix, that deliver to maildirs. A Courier/Postfix combination is highly popular.
If you already have Courier installed, you do not need to download this version. However, if you decide to install this standalone version, you must remove it if you later install the entire Courier server. You can have both versions installed, but it requires delicate juggling.
In conclusion, if you are looking for a fast, scalable, and efficient enterprise IMAP server to handle a large number of mail accounts, Courier-IMAP is an excellent choice. Its focus on Maildirs makes it a popular option for Qmail, Exim, and Postfix sites, and its unique features such as the built-in IMAP and POP3 aggregation proxy set it apart from other IMAP servers.
Version 4.5.0: N/A