Version:            (using KDE 4.2.90)
Installed from:    SuSE RPMs

There is something horribly inefficient in kmail's handling of message transfers between imap folders on the remote server that makes it look like kmail is copying the message to the local computer and then copying them back to the new folder on the remote server.

I have used thunderbird for years, but with kde4, I resolved to use kmail. POP handling seems fine, but imap handling seems horribly slow compared to thunderbird. I manage the mail server I am connecting to so I can provide logs or other information if you need to look at the server communications.

With tbird, when doing large moves between folders on the server, it looks like tbird just submits a list of what needs to be done to the server and it happens instantly. With kmail, you start the same transfer and then the status indicator rambles around on the lower right of the status bar for a few minutes and if you select the details you see every message being individually handled as the list scrolls up and down the page.

Somehow, there must be a way to improve the imap handling so kmail performs a bit better. I don't know what the different ways are to do the message manipulation between folders with imap, but I do know that kmail appears to take 10 times as long to do the same imap message transfers compared to thunderbird.

I think kmail has really made many great improvements in its kde4.3 beta state, but this is one are that really needs work. Thanks.