Managing IMAP

When Is Cyrus the Right Choice?

The Cyrus server’s design is a quite different approach to IMAP than the UW server. The UW server emphasizes personal mailboxes, while Cyrus supports both personal mailboxes and shared mailboxes equally. The Cyrus server’s closed, or black box, design makes access to the Cyrus mailstore faster than access through the UW server. There is, however, a trade-off for that performance improvement, such as the inability of users to log in to the server. If there’s a need to move mail from a Cyrus server to a traditional Unix mail system or UW server, then there’s more to moving it than a simple file copy. The mail must either be translated back through the IMAP protocol or suitably munged using a translating script that copies the mail back into the appropriate format via a filesystem protocol (such a script is provided in Chapter 9 ).

Here are some criteria that a site can use to determine whether the Cyrus server is a good match:

• Do users need to share private mail folders with other users?

• Is there a per-user limit on the amount of space the user can occupy in the mailstore?

• Does the site need to provide public forums with controlled access (i.e., bulletin boards)?

• Does the site require encrypted authentication?

• Does the site anticipate fast growth in the number of users on the system?

If a site answers yes to the above criteria, then Cyrus is the best choice.