Would it be sufficient to simply not process large messages for that user? The distro procmailrc.example file shows how set a limit on message size processed in your .procmailrc:
:0fw: * < 256000 | spamassassin sets a limit of 256K, or you could pick a much smaller number. -- Alayne McGregor alayne at twobikes.ottawa.on.ca "I am not amused by this 21st century. I want to take it back for a full refund, and can we have a real one, please?" -- Charles Stross (Locus, January, 2005)
