I am trying to move a domain (website and email server) from a Windows 2003 server to a Linux server. Moving the website and database over has been tedious (but successful) but I'm not sure how to move the IMAP mailboxes.
I've done many server migrations before but always with *nix servers, where I have either used a cPanel transfer or a set of rsync scripts but Windows doesn't have rsync and anyway I don't have access to the mail folder structure to just copy it over.
The Windows hosting company have suggested that I ask all the users to manually copy their emails from the old server accounts to the new accounts, but this is a lot of clients and GBs of mails and will take a long time.
Can I ask them to zip up a mail folder and send it to me? Does Windows have a standard mail folder structure 'under the hood'?
OK, I tried Larch: installs and runs very easily, standard YAML file format. Didn't copy any files though, so a bit useless. I suspect that is because it is a Windows source server. Probably works for Linux.
imapsync: worked very well. I use a git clone copy and it copied all the mails over.
Note that you don't need to run imapsync on the same machine as either of the mail servers, it's also possible to run on another machine as these are true imap connections.