I'm writing a simple web app with which people can migrate their email from one server to another. I've read about imapsync and tried it out. So far it works very good and seems to be a good solution. At the end of the migration it tells me it had used ~ 350 MB of memory.

Another possible solution is the imap-move PHP script. It has its own GitHub page here: https://github.com/edoceo/imap-move. I can't seem to find out how much memory it uses.

I want ~ 30 users to be able to use the web app at the same time, without running out of memory. I want to test which solution is the fastest and/or uses the least memory, but don't know how. Any suggestions?

  • I used larch (ruby) back in the day, but eventually moved to bittitan Dec 6, 2016 at 4:42
  • Does BitTitan enable you to let your customers migrate their email, or is it a tool you can use yourself?
    – SomeCode
    Dec 6, 2016 at 9:02
  • yes both, you can enter your creds or delegate access Dec 6, 2016 at 11:46

2 Answers 2


Nothing I've ever seen beats the quality and reliability of imapsync. What it does appears to be an easy problem but it's really not and Gilles has worked out countless small problems over the years that plague other solutions. The solution you linked has only one commit over four years ago and I wouldn't waste a single second on this because it almost certainly will not work as well as imapsync - most likely it will only work in the specific setup the author tested it on anyway.

  • 1
    Imapsync was the best investment I've ever done.
    – Uwe Keim
    Dec 6, 2016 at 12:17
  • 1
    Well Uwe, this is great great words for me! Thanks! Feb 28, 2017 at 20:00

I also wrote an online GUI for imapsync, Imapsync online. It has run with success for more than a month. Imapsync has now a builtin load discharge mechanism upon online context: when the load is too heavy then imapsync quit and ask to come back later. It never happened so far on this small 2GB 4 cores server. Feel free to use it!

  • 1
    Wow, you're awesome. :)
    – SomeCode
    Mar 1, 2017 at 12:26

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