isync: free IMAP and MailDir mailbox synchronizer

isync is a command line application which synchronizes mailboxes; currently Maildir and IMAP4 mailboxes are supported. New messages, message deletions and flag changes can be propagated both ways. isync is suitable for use in IMAP-disconnected mode.

Synchronization is based on unique message identifiers (UIDs), so no identification conflicts can occur (as opposed to some other mail synchronizers).
Synchronization state is kept in one local text file per mailbox pair; multiple replicas of a mailbox can be maintained.

isync is free software in the sense of the GNU GPL v2.



isync should work fairly well with any IMAP4 compliant server; particularily efficient with those that support the UIDPLUS and LITERAL+ extensions.
Courier 1.4.3 is known to be buggy, version 1.7.3 works fine.
c-client (UW-IMAP, Pine) is mostly fine, but versions less than 2004a.352 tend to change UIDVALIDITY pretty often when used with unix/mbox mailboxes, making isync refuse synchronization. The "cure" is to simply copy the new UIDVALIDITY from the affected mailbox to mbsync's state file. This is a Bad Hack (TM), but it works - use at your own risk (if the UIDVALIDITY change was genuine, this will delete all messages in the affected mailbox - not that this ever happened to me).


While isync is the project name, mbsync is the current executable name; this change was necessary because of massive changes in the user interface. An isync executable still exists; it is a compatibility wrapper around mbsync.



Please use the mailing list for feedback.
Last update: Wed Dec 18 22:26:23 CET 2013.

Hosted by SourceForge Logo