Charles Gregory wrote: > On Mon, 11 Aug 2008, rick pim wrote: >> > > prime advantages of greylisting -- the fact that it will never >> > > block 'real' mail -- turns out, um, not to be true. there are so many >> > > standards-noncompliant MTAs out there.... >> ...... some of the offenders are high profile, fortune-500 companies. > > Could I just clarify this discussion? It started out with a specific > comment about greylisting, which I am preparing to implement. So naturally > it concerns me as to whether these remarks about 'big name' non-compliant > MTA's still apply specifically to greylisting. I mean, I can't really > imagine a 'big' (fortune 500?) company having an MTA that does not attempt > to resend mail if it gets a 400 response from another MTA. I realize they > break all sorts of other stuff. Non-compliant 'helo's and all that, but at > least please tell me there isn't a 'big' company out there that is failing > to handle 4xx codes properly.... (holding breath)
There are some big names that play badly with greylisting. They play badly with greet-pause, too. A problem I've seen with greylisting is the round-robin MTA pool. Each is told in turn to come back later and if the pool is large it can take a long time to cycle through all of them. You have to be careful how you screen the addresses. dp _______________________________________________ Help us build a comprehensive ClamAV guide: visit http://wiki.clamav.net http://www.clamav.net/support/ml
