Aah, yes, but this is called from a system-wide procmail file.
Yeah? so? Set up a procmail rule to bypass the call to spamc when the recipient is the user you don't want scanned.
System wide vs per-user calls of procmail does not matter here.. it's a matter of knowing how powerful procmail is.
Heck, some people even expand it to use a perl script which checks for the recipient in a list in a file as their bypass critera:
http://www.mail-archive.com/spamassassin-talk@lists.sourceforge.net/msg08302.html
