Rate limiting IMAP connections

[Michael D. Sofka]

How can I rate limit IMAP connections?  There are a few, just a few, users who 
insist they need to see email instantly using clients that connect, check 
email, disconnect----multiple times per minute.

I recall reading somewhere of a way to do this in PAM, which would be ideal 
since it would require minimal server reconfiguration.  But, now I cannot 
find the source and in this case my good friend google has not come through.

Suggestions?

Mike
-- 
Michael D. Sofka               sofkam at rpi.edu
C&MT Sr. Systems Programmer,   Email, TeX, Epistemology
Rensselaer Polytechnic Institute, Troy, NY.  http://www.rpi.edu/~sofkam/