The Secure IMAP server
Dovecot is an open source IMAP and POP3 email server for Linux/UNIX-like systems, written with security primarily in mind. Dovecot is an excellent choice for both small and large installations. It's fast, simple to set up, requires no special administration and it uses very little memory.
Dovecot's indexes are self-optimizing. They contain exactly what the user's client commonly needs, no more and no less.
Dovecot is self-healing. It tries to fix most of the problems it notices by itself, such as broken index files. The problems are however logged so the administrator can later try to figure out what caused them.
Dovecot tries to be admin-friendly. Common error messages are made as easily understandable as possible. Any crash, no matter how it happened, is considered a bug that will be fixed.
Clustered filesystems compatibilty
Dovecot allows mailboxes and their indexes to be modified by multiple computers at the same time, while still performing well. This means that Dovecot works well with clustered filesystems. NFS has caching problems, but you can work around them with director proxies.
Dovecot supports workarounds for several bugs in IMAP and POP3 clients. Since the workarounds may cause the protocol exchange to be suboptimal, you can enable only the workarounds you need.
- Complete IMAP4rev1 and POP3 support. IPv6, SSL and TLS are supported.
- Supports multiple commonly used IMAP extensions, including SORT, THREAD and IDLE.
- Shared mailboxes are fully supported in v1.2+. Older versions also support admin-configurable ACL files.
- Maildir++ quota is supported, but hard filesystem quota can be problematic.
- Dovecot is commonly used with Linux, Solaris, FreeBSD, OpenBSD, NetBSD and Mac OS X. See the Wiki page about OS compatibility for more.