Any ideas on limiting the total number of SMTP messages processed per day?

[Jim Munroe (NETONE)]

Hi,

Anyone have any ideas on how to limit the number of SMTP msgs sent by a
given host/IP over a duration of time?  For example, users are only
allowed to send a total of 200 SMTP messages per day through a given mail
relay then they are blocked (IPTables or Access file) until the next day.

We do something like this today using MailScanner and Vispan to limit the
total number of virii/spam msgs per IP.

Any help or suggestions would be greatly appreciated!

Thanks,

Jim