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Dovecot IMAP Information

Of the two mailbox formats, mbox and Maildir, almost all users will stay with the default, which is mbox. Only if you have a very large mailbox or sever performance issues should you consider moving to Maildir. Contact tstaff at problem@cs.brown.edu for help if you feel you would benefit from Maildir.

MBOX Format

mbox is an older, yet still fully capable, mailbox format where all mail messages for a particular folder are stored in a single file on the server.

Advantages:
* Easy to search mail files using Unix utilities (grep, less, etc..)
* Easy integration with console based mail programs
* Easier searching via imap clients
* Almost any email client out there can import email in mbox format
* Entire legacy of tools to manipulate, archive, and manage mbox files

Disadvantages:
* Folders can't contain sub-folders
* Performance and mail access speeds decrease drastically as mail
boxes become large (> 1G total mail)
* Does not support multiple IMAP clients connecting simultaneously
* Corruption of a single message can affect all other messages stored in the same mbox file

Maildir Format

Maildir is a newer format, where each email message is stored in a separate file.

Advantages:
* Much faster when dealing with large amounts of mail (> 1G total)
* Supports multiple IMAP client connecting simultaneously
* Folders can contain sub-folders

Disadvantages:
* Searching is slower. This is mitigated to some extent by client and server side indexing
* Much harder to use standard Unix utilities (grep, less, etc..) as email messages are each in their own file.
* Fewer console-based mail readers support Maildir format. Usually, console-based mail readers must be configured in IMAP mode.

Page Owner: tstaff Last Modified: Thu Mar 13 10:31:25 2008