On Wed, 7 Jan 1998, Kevin P. Fleming wrote:
Recently, I modified the sendmail.cf file to pipe messages through procmail
before sending them to deliver, so that I can use system-wide procmail
recipes for spam filtering. However, yesterday we had a client send a 22
megabyte e-mail message (on purpose, no less) and the system just came to
its knees trying to deliver it to the user's mailbox.
Procmail uses as much memory as the largest message you are going to
deliver. Procmail is an incredibly stupid piece of software.
So 22M + whatever you were currently using = more memory than you had
available.
Spam filtering is much more efficiently done in the MTA, especially if
you just looking at From and To lines. For example, I have setup in Exim
a rule that blocks \d(_dot_)*(_at_)aol\(_dot_)com (that is any aol.com local
part that
begins with a digit). AOL guarrentees that _none_ of their addresses
being with a digit. Exim rejects such bogus addresses at the SMTP level
before the message is received.
Tom