Thanks for the suggestion. I did this and here is the relevant part of the log file for a sample email:
procmail: Assigning "DROPPRIVS=yes"
procmail: Assuming identity of the recipient, VERBOSE=off
procmail: Assigning "PATH=/bin:/usr/bin:/usr/local/bin"
procmail: Assigning "SHELL=/bin/sh"
procmail: Executing "/usr/bin/spamassassin"
/bin/sh: /usr/bin/spamassassin: Permission denied
procmail: Program failure (126) of "/usr/bin/spamassassin"
procmail: Rescue of unfiltered data succeeded
I'm still stumped, however. The permissions for spamassassin seem to be correct:
-rwxr-xr-x 1 root root 27021 Sep 14 18:29 /usr/bin/spamassassin
I can run it from the command line, so I'm not sure why I'm still getting "permission denied." Do I need to change the ownership of spamassassin?
I could only find one relevant posting with a similar error (located here
http://use.perl.org/~samtregar/journal/29278), but that doesn't sound like my problem.