Dovecot Description
Dovecot is a great choice for both small- and large-scale installations.
Dovecot is one of the fastest IMAP servers, and it still supports the standard Maildir and mbox formats. Dovecot's high performance is due to the transparent indexing of mailboxes.
Dovecot is compliant with standards. Dovecot is compliant with all IMAP server standards.
Dovecot's Indexes are automatically optimized. They contain only what the client of the user needs most often, nothing more or less.
Dovecot has self-healing capabilities. It fixes most of the problems that it finds on its own, like broken index files. The problems are logged, however, so that the administrator can try to determine what caused them later.
Dovecot strives to be administrator-friendly. The common error messages are as clear as possible.