Re: clarification re 2821, s4.1.4

What the standard says is: If the EHLO parameter doesn't match the 
client, you can write scary messages in the response, and you can 
tarpit the conversation (sending 100-line multiline responses at 20 
seconds per line) to slow down the presumed spammer, and you can do 
lots of other things, but you can't refuse the mail outright.
--Arnt