[mdlug] Quotas. How do they work?

[Robert Adkins II]

I am seeking to force certain users into trimming back the size of their
email stored on the IMAP server. Much of the data itself doesn't need to be
stored in email long term, as it is replicated elsewhere on the network.
 
The problem is, if I just toss in a quota I am concerned that there will be
no warning, just suddenly they will be unable to send/receive email. Nothing
I am seeing the in the tools for enabling quotas suggests that the users
will receive any form of warning.
 
Is this true?
 
Thanks,
Rob