No, luckily not. But we have a lot of users with 10-20 MB, quite a lot with
50-100, and some hundred with 100+ MB. Many of our users leave their mail on
the server - and we cannot (and will not) avoid it.
So, use IMAP-SSL. Introduce it for those who wish to leave their mail on
the swerver, and especially for those who have large amounts of mail. You
can run both POP3 and IMAP at the same time, and it's not that hard to
"train" users to set up IMAP accounts.
Once they start using IMAP, they'll thank you for introducing it.