On 3/30/2016 6:24 AM, Miles Fidelman wrote: > > Hi Folks, > > I'm busily trying to tune our system to reduce the amount of bounceback > we generate. (Wietse - thanks for earlier reply!) > > Context: Postfix mail system, with sympa mailing list manager. > > Obviously, I'm doing what I can to discard incoming mail with forged > addresses.. still a struggle. > > One obvious thing that I did was to changed the "bounce" lines in > master.cf to "discard" - which has eliminated multiple attempts to > deliver messages to addresses that accept-then-bounce. > > But I'm still seeing things like this: > Mar 29 14:10:44 server1 postfix/smtp[13617]: 0320DCC5E0: > to=<substanceab...@expern.top>, > relay=o4pz11.expern.top[216.169.122.211]:25, delay=1373, > delays=1193/0.05/0.31/180, dsn=4.4.2, status=deferred (conversation > with > o4pz11.expern.top[216.169.122.211] timed out while sending message > body) >
Don't accept mail you can't deliver. Surely this mail would have been blocked by zen.spamhaus.org before it entered your system. And the .top TLD is an excellent candidate for blacklisting before it enters your system. > Where messages are getting rejected during the smtp phase > (presumably by > header checks and/or blocklist checks) - what's the magic configuration > change to have these discarded rather than deferred? The "timed out" means the receiving system stopped responding. Probably the spammer's system is overloaded with others trying to return undeliverable mail. Don't accept mail you can't deliver. -- Noel Jones
