On Nov 13, 2014, at 15.02, Noel Jones <njo...@megan.vbhcs.org> wrote: > > On 11/13/2014 11:14 AM, b...@bitrate.net wrote: >> hi- >> >> short version: >> i have an mx which, after doing the initial handling [postscreen, etc] of >> messages arriving from the internet, relays mail to another computer for >> content filtering [amavis/spamassassin]: >> >> relay_transport = lmtp-filter:[mfa.example.com]:lmtp-filter-external >> >> after a message has been accepted, i'd like to delay its relay to the >> content filter for five minutes. can postfix do this? >> >> longer version: >> i've noticed a recent trend in which a message arrives, passes >> postscreen/various smtpd_*_restrictions, and is passed to the content >> filter, which passes it as clean, having not matched many rules [in >> particular, network tests like uri dnsbls, razor/pyzor, etc]. >> >> minutes later, the same message arrives [timestamps, message ids, etc >> differ], in that time has made its way into the results of various network >> tests, and is then marked is spam. >> >> e.g. my consideration for this approach. i'd also be interested in general >> thoughts on this problem, and other possibilities. i'm not particularly >> fond of artificial delays, and the various implications [e.g. queue sizes, >> user expectations, etc], but in the context of a controlled environment >> [e.g. after postfix has accepted the message, i'm willing to at least >> entertain the possibility. >> >> thanks-ben >> > > This is exactly why greylisting was invented. Have you tried that?
i don't know about "exactly", but yes, i did briefly consider that greylisting would have a somewhat similar effect. it would introduce a delay, but at the cost of all of the other side effects of greylisting, which would likely cause more problems than it would solve, imho. that's why i wanted to do it after the message was accepted, where the onus can be fully on me regarding its fate. -ben
