I have an IMAP E-Mail account with my old provider.

I have a new, empty IMAP account with the new provider.

Is there a tool or Thunderbird to migrate the E-Mail data from one account to another? I'm a bit wary about just doing a drag & drop in Thunderbird because it's quite a lot of data, and I have a deep distrust against how Thunderbird deals with IMAP data.

I'm working on Windows 7, so I would prefer a graphical Windows tool. If need be, I can work from a Linux box as well.

6 Answers 6


Be carefull when draging and dropping IMAP to check the contents of any subfolders. Different flavours of IMAP handle subfolders differently and with some thuderbird will transfer the folder but not its contents. I've found the best mail client for draging to/from Courier IMAP accounts to be Mulberry. http://www.mulberrymail.com/ - Its a bit retro but does the job.

If you end up using a syncing tool, you run the risk of ending up with duplicates. In that case there is a Thunderbird plugin that will remove them for you but it can gag on large inboxes. https://addons.mozilla.org/en-US/thunderbird/addon/956


Try using imapsync, available also as a standalone imapsync.exe. Free, open but not gratis from the homepage.

  • Cheers sntg, but I'm on Windows with this. Sorry, should have mentioned it - adding it now.
    – Pekka
    Apr 1, 2010 at 21:54
  • 1
    imapsync is written in Perl. Should run run in Windows as well. Apr 2, 2010 at 7:17
  • 2
    Not free at 50 euros. Apr 9, 2015 at 8:23
  • 1
    impaysync.exe is not free... Any alternatives? Jun 28, 2016 at 21:58
  • 1
    Imapsync now has an online version: imapsync.lamiral.info/X Aug 22, 2017 at 16:39

An excellent tool for Windows is MailStore Home (free)

  1. You install it on your PC

  2. then you Archive all your emails from IMAP Account1 on Server1

  3. you simply Export all your previously archived emails to your IMAP Account2 on Server2

It works also with IMAPS (SSL), and it archives/exports all IMAP folders (or only the ones you wish).

Note: so far I've tried it only to export all messages from one mailbox account to another one. The two mailboxes were on different servers, but both servers run cPanel/WHM accounts, thus both servers' environments were pretty similar.

  • 1
    BEST SOFTWARE EVER! SAVED MY LIFE! Sep 11, 2019 at 16:55

We used Hexamail POP3 Downloader to synchronize our IMAP accounts during our server move. It runs on any version of Windows and has a GUI to help you configure it. You need to add the IMAP Push module to push email back up to IMAP Accounts.


I'd recommend the drag and drop, but do it in manageable chunks, e.g. 1 month at a time. You could also copy down to a local directory first, then up to the new server.


Like sntg, I'd try using imapsync first (should also run under Windows with ActivePerl).

If you can't get it to run, try imapsize which can - besides a lot of other things - migrate your mails between two IMAP accounts.

  • From recent experience migrating imap accounts using imapsize, it changes the dates on all the migrated emails to the migration date. If anyone know's how to get it to keep the original date please let me know.
    – Rich
    Aug 19, 2012 at 14:52
  • "NOTE: Please be advised that IMAPSize is no longer under active development since 2009" Feb 3, 2016 at 12:06

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