Tuesday, May 17, 2005

I've run into yet another naive attempt to control spam -- systems that try to verify the mail sender using the SMTP VRFY command. The problem is that a system that relays mail might report the address as invalid because it is not a local address even though it really is valid when relayed.

I've run into this only a few times so far and hope that those who use this algorithm see the naivete of their ways sooner rather than later. Unfortunately they may remain ignorant since they have isolated themselves. It's like asking people who can't hear you to raise their hands. So, if you know someone who is rejecting valid mail just because it failed a verify, please help them reconnect with the rest of us.