- I don't use such a MUA (instead I use mutt), which makes it unneccessary hard, because I really need to setup the accounts
- Most graphical MUAs I know are bad at working with a great number of mails. At least Thunderbird does not even properly show what he is doing and how long he is supposed to doing it
- imapcopy
- imapsync
I had a quick look at imapcopy and it did not have a proper manpage.
Instead it refers to the built-in help (imapcopy -h) which is not useful either and to examples in /usr/share/doc.
After that I had look at imapsync. It comes with a pretty good manpage and a pretty good built-in usage information. Appearently I rate it very important that either the manpage or the built-in help are good enough to get started with a tool. Certainly I know that tools exist where a manpage is simply not enough, but I guess a tool to sync imap folders is not one of them.
After studying the manpage for about 2 minutes I was ready to construct a command line and give it a --dry try. This parameter lets me see what the tool would do if I would ommit it. That one looked good and so I gave it a shot. It then started to work. It has two flaws.
- Unfortunately it does not indicate its progress and the normal messages are not a good help either, because they contain numbers that actually do not refer to mails in one of the mailboxes (they are soon literally higher as the number of mails in both mailboxes) and I do understand what it is referring to.
- It sometimes crashed at random locations with random messages. I didn't look deeper into it, because restarting the script helped and therefore I cannot speak of a easy reproducible problem. In 3000 mails it happened about 1-2 times, so not a great deal but still annoying.