The Courier IMAP server - Feature
Summary
- Extremely small footprint. On x86, the Courier IMAP server's main daemon is a
fraction of the size of the UW-IMAP server, and has
a greatly reduced memory footprint.
- Uses the Courier
Authentication Library for authenticating mail
accounts.
- Ability to restrict the maximum number of
IMAP logins, and the
maximum number of logins from the same IP address. This
will prevent denial-of-service attacks where the attacker
attempts to overload the server with multiple login
connections.
- Shared folders. With additional server-side setup,
folders can be shared between groups of accounts.
- IMAP over
SSL. If OpenSSL or GnuTLS is installed, the
Courier IMAP server will,
optionally, accept IMAP
connections over SSL.
The IMAP STARTTLS
extension is also implemented.
- Authentication using SSL certificates.
- IPv6 support, if available.
- IMAP extensions that
implement server-side sorting. This can be optionally
disabled in environments that have limited resources.
- The Courier IMAP
server implements many popular IMAP protocol extensions that provide
value-added functionality with most popular IMAP clients.
- Sorting and searching in non-English character sets.
Download the source code to obtain a list of currently
supported character sets.
- A compatible POP3
server is also included in the Courier IMAP server package, that uses
the same authentication modules. The POP3 server can only access the INBOX,
and cannot access any folders.
- An experimental mail access protocol, SMAP.
- IMAP/POP3 proxying. It is possible to
distribute all mailboxes between multiple servers. A
separate server (or a pool of servers) accepts all
IMAP/POP3 connections, then connects to the
right server based on the mailbox the connecting client is
logging into.