wayne wrote:
Slight correction. Striker never did that AFAIK. Striker always rejected, via either outright denial of connection or inline rejects rather than bouncing or accepting. The unproven supposition is that his problem is because of one or two malfunctioning dictionary runs. There's on the order of 1500 or so unique destinations in the load.If you silently accept email with invalid recipients, you may well end up in the same position as Alan DeKok. (see http://www.striker.ottawa.on.ca/ and his several million spams per day) Spammers often have more bandwidth than you do, and often care less about wasting it (since it is often stolen bandwidth.) Trying to get spammers to waste their bandwidth by consuming yours doesn't sound like a good idea to me.
Multiple "RCPT TO" then "QUIT" is the same as VRFY.Similarly, I'm not sure that disabling the VRFY SMTP command is a good idea. Yes, the VRFY command can be easily used by spammers to do a dictionary attack on your server, but if you don't let them do it the "easy" way, they will likely do it the "hard" way by sending spam to every possible email address.