I'm currently running IMAPsync on CentOS and I'm getting out of memory errors. The problem I'm having is that I'm using the smallest mailbox as a test case, and it's not helping my confidence level to have out of memory errors on a 2G mailbox.

I assumed from the description on the page that is was a recursive program, so I expected it to continue from where it left off, but I have no idea if it did that on the second run or not.

Is it possible to have IMAPsync continue until both mailboxes are in sync, or at least till all the mail from host1 has been moved to host2?


  • What flags are you passing it? You should be passing "--useheader 'Message-ID'", for example. Dec 30, 2011 at 2:56
  • ./imapsync \ --host1 imap.domain.A --user1 foo --password1 secret1 \ --host2 imap.domain.B --user2 bar --password2 secret2 And also using --split1 100 --split2 100 Dec 30, 2011 at 3:35
  • There is also a FAQ entry about memory issues in imapsync's docs here: imapsync.lamiral.info/FAQ.d/FAQ.Memory.txt
    – balupton
    Feb 16, 2022 at 1:17

1 Answer 1


The memory issue is solved by using Perl module Mail-IMAPClient >= 3.26


  • I seem to have been able to sync some massive 10G+ mailboxes using -useheader 'message-id' and also using --dry to make sure everything connects as expected. I'll update my Perl modules as well. Jan 4, 2012 at 15:41

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .