[Dovecot] Performance question

[Stewart Dean]

I now have Dovecot in production and things are apparently trouble-free. 
The one known problem is that initial client inbox load can take 30 
seconds - 2 minutes.  For instance:
'I got fed up waiting and went and got coffee'...this with a 3MB mbox 
inbox...and my mail server is a substantial machine consuming 25% CPU 
just for this person's IMAP session.
I realize that a certain amount of performance piggishness is inevitable 
with large mbox inboxes (the prize goes to the user with a 500MB 
inbox).  Eventually, I plan to move to maildir format, but for now I'm 
here.  Also, we have legacy requirement for procmail, so I can't 
currently use deliver.

Questions:
1) Any tuning I can do to improve this?
2) Any metrics, troubleshooting I should be doing to better characterize 
the problem?

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Stewart Dean, Unix System Admin, Henderson Computer Resources 
Center of Bard College, Annandale-on-Hudson, New York  12504  
sdean at bard.edu  voice: 845-758-7475, fax: 845-758-7035