[Dovecot] Large Mailbox Slow

[Matt]

Doubt if there is any answer to this but will ask anyway.  Have a few
pop3 accounts with thousands of messages.  Its slow when checking
email naturally.  Are there any tweaks to speed it up?  I imagine
there is an exchange of the message and header list which is the slow
down.  Too bad the list could not be compressed with gzip or something
first.  I think http has an option similar to that.

Just asking.