I am using KMail for IMAP on folders containing more than 10000 messages
For me, the problem becomes severe when the folders approach 1000 messages.
Though I do use Cyrus IMAPd, not Courier.
This is an interesting idea. Does anyone have these slowdowns with cyrus or conversely not have any problems with courier?
Maybe KMail wants to reindex the folder and does it in a way, where Courier becomes heavily loaded.
I have suspected something along these lines since the slowdowns seem to coincide with reading the headers for a folder that has new messages since the last access. Also, the progress meter in the lower-right of the kmail window completes repeatedly during this process.
Does KMail do any network transfers while it is stuck (is it downloading large amounts of data, or sending a large number of commands to the server?)
For me, the problem is there but not as severe when I run kmail on the server. From the local network the slowdowns are a bit worse. Remote access is noticeably worse. From this I infer that there is a lot of network traffic. Is there a better way I could test this that would yield more helpful information?
Courtney