[HowTo] Replace courier with dovecot

[simple]

After successfully switching to dovecot to speed up the imap access a few months back, I was pretty happy with the result. A few months later the mail access speed dropped rapidly to levels even slower than courier was before. Does dovecot have some known limits I didn't see? The mail folder is pretty big, some couple 100 folders and approx 100.000 mails all together (5gig space used).

The courier speed was always a little slow, but ok to work with, dovecot was pretty much faster to start with, and is way slower now

Someone came across this problem before? I could find no help/reference in google.