martin f krafft <[EMAIL PROTECTED]> writes: > Anyway, I'll be interested to hear a summary of their arguments, as > Christian Perrier requested. I find it hard to imagine how properly > configured greylisting should cause any problems.
It's a violation of the standard. It is especially problematic, because it is a violation against the spirit of being liberal in what you accept, and conservative in what you require. It assumes, for example, that the remote MTA will use the same IP address each time it sends the message. If the remote MTA is a big server farm, with a lot of different hosts that could be processing the mail, what is your strategy for preventing essentially infinite delay? So far, all I have seen in response to this particular problem is to say that "properly configured" includes an exactly accurate hardcoded list of all such sites on the internet. Another problem is with hosts that do not accept a message from an MTA unless that MTA is willing to accept replies. This is a common spam prevention measure. The graylisting host cannot then send mail to such sites until they've been whitelisted, because when they try the reverse connection out, it always gets a 4xx error. I've been bitten by this one before. Thomas -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]