So I'm late to the party here, but I just came across IGNORABLE_404_STARTS and IGNORABLE_404_ENDS. I'm trying to make use of this, but it isn't working for me. For instance, I set:
IGNORABLE_404_ENDS = ('mail.pl', 'mailform.pl', 'mail.cgi', 'mailform.cgi','favicon.ico', '.php')
If I go to http://www.mysite.com/test/mail.cgi, I will still get the 404 error message emailed to the admin account. Am I missing something here? My reading of the docs led me to believe that this case wouldn't generate an email.