Mailbox Formats =============== Mailbox formats supported by Dovecot: +-----------------------------+---------------+-------------------+-------------+ | *Name* | *Tag* | *Description* | +-----------------------------+---------------+-------------------+-------------+ | <mbox> | 'mbox' | Traditional UNIX | | [MailboxFormat.mbox.txt] | | mailbox format. | | | | Users' INBOX | | | | mboxes are | | | | commonly stored in| | | | '/var/spool/mail' | | | | or '/var/mail' | | | | directory. Single | | | | file contains | | | | multiple messages.| +-----------------------------+---------------+-------------------+-------------+ | <Maildir> | 'maildir' | One file contains | | [MailboxFormat.Maildir.txt] | | one message. A | | | | reliable choice | | | | since files are | | | | never modified and| | | | all operations are| | | | atomic. The | | | | top-level | | | | 'Maildir' | | | | directory contains| | | | the 'Maildir/cur',| | | | 'Maildir/new' and | | | | 'Maildir/tmp' | | | | subdirectories. | +-----------------------------+---------------+-------------------+-------------+ | <dbox> | 'sdbox' | *single-dbox*, one| Dovecot's | | [MailboxFormat.dbox.txt] | | message per file | own high | | | | | performance | | | | | mailbox | | | | | format. | | | | | Messages are| | | | | stored in | | | | | one or more | | | | | files, each | | | | | containing | | | | | one or more | | | | | messages. | +-----------------------------+---------------+-------------------+-------------+ | 'mdbox' | *multi-dbox*, | | | multiple | | | messages per | | | file | +-----------------------------+---------------+-------------------+-------------+ | 'dbox' | deprecated | | | alias for | | | 'sdbox' | +-----------------------------+---------------+-------------------+-------------+ | <Cydir> | 'cydir' | Dovecot's own | | [MailboxFormat.Cydir.txt] | | simple and high | | | | performance | | | | Cyrus-like mailbox| | | | format. It should | | | | be mostly used for| | | | testing and | | | | benchmarking only.| +-----------------------------+---------------+-------------------+-------------+ | <imapc> | 'imapc' | Use remote IMAP | | [MailboxFormat.imapc.txt] | | server as mail | | | | storage. | +-----------------------------+---------------+-------------------+-------------+ | <pop3c> | 'pop3c' | Use remote POP3 | | [MailboxFormat.pop3c.txt] | | server as mail | | | | storage. | +-----------------------------+---------------+-------------------+-------------+ The *Tag* column indicates the tag which is used at the beginning of a <mailbox location specification> [MailLocation.txt]. Mailbox formats *not* supported by Dovecot: +-------------------------------+---------------------------------------------+ | *Name* | *Description* | +-------------------------------+---------------------------------------------+ | <mbx> [MailboxFormat.mbx.txt] | UW-IMAP's old high performance mailbox | | | format. One file contains all the mailboxes,| | | so expunges may still be slow. | +-------------------------------+---------------------------------------------+ | <mix> [MailboxFormat.mix.txt] | UW-IMAP's new (2006) high performance | | | mailbox format. Similar to multi-dbox. | +-------------------------------+---------------------------------------------+ | <mailstore> | A format created by Exim. | | [MailboxFormat.mailstore.txt] | | +-------------------------------+---------------------------------------------+ | <MH> [MailboxFormat.MH.txt] | One file contains one message. Sort order of| | | the folder determines the message ID and | | | name. Actively used by projects such as | | | MH-E, NMH, exmh. Experimentally supported | | | by UW-IMAP [http://www.washington.edu/imap/].| +-------------------------------+---------------------------------------------+ | <MMDF> [MailboxFormat.MMDF.txt]| Similar to mbox, but instead of From-line | | | separators it uses four '^A' characters | +-------------------------------+---------------------------------------------+ | <Cyrus> | One file contains one message, plus there | | [MailboxFormat.Cyrus.txt] | are a couple of index/cache files. Commonly | | | referred to as being maildir-like, although | | | they have only a single thing in common. | +-------------------------------+---------------------------------------------+ Adding support for new formats for Dovecot isn't very difficult, although it can be time consuming. Dovecot exposes a nice and simple API which needs to be implemented. Use Cydir format as an example. Software Support ---------------- +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ | *Format/Software* | *Dovecot | *UW-IMAP | *Courier-IMAP | *Exim | *Postfix | *PINE | *mutt | *procmail | *maildrop | | | [http://www.dovecot.org/]* | [http://www.washington.edu/imap/]* | [http://www.courier-mta.org/imap/]* | [http://www.exim.org/]* | [http://www.postfix.org/]* | [http://www.washington.edu/pine/]* | [http://www.mutt.org/]* | [http://www.procmail.org/]* | [http://www.courier-mta.org/maildrop/]* | +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ | <mbox> [MailboxFormat.mbox.txt]| Yes | Yes | No | Yes | Yes | Yes | Yes | Yes | Yes | +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ | <mbx> [MailboxFormat.mbx.txt] | No | Yes | No | Yes | No | Yes | No | No | No | +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ | <maildir> | Yes | No | Yes | Yes | Yes | No | Yes | Yes (3.22) | Yes | | [MailboxFormat.Maildir.txt] | | | | | | | | | | +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ | <mailstore> | No | No | No | Yes | No | No | No | No | No | | [MailboxFormat.mailstore.txt] | | | | | | | | | | +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ | <dbox> [MailboxFormat.dbox.txt]| Yes | No | No | No | No | No | No | No | No | +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ | <MH> [MailboxFormat.MH.txt] | No | Yes | No | No | No | Yes | Yes | Yes | No | +-------------------------------+----------------------------+------------------------------------+-------------------------------------+-------------------------+----------------------------+------------------------------------+-------------------------+-----------------------------+-----------------------------------------+ Conversion Between Mailbox Formats ---------------------------------- See <Migration.MailFormat.txt>. References ---------- * Mutt mailbox formats: http://rucus.ru.ac.za/docs/mutt/manual58.html * Article on mailbox formats: http://www.livejournal.com/users/rfunk/1571.html * Mbox and maildir comparison: http://www.linuxmail.info/mbox-maildir-mail-storage-formats/ (This file was created from the wiki on 2017-05-11 04:42)
