On 6/15/2017 7:37 PM, Brett Maxfield wrote: > in short : > > can we do and queries and bind several different > (sender|recipient)_checks with an AND logic ?
Yes, you can do all sorts of clever and complex checks with an external policy service. http://www.postfix.org/SMTPD_POLICY_README.html > can we configure some classes of failures, such as dns, to fail more > quickly ? Generally, no. If something fails with a temporary error, how to reliably automatically distinguish between a "real" site that's temporarily down from something that will never work? Postfix can reject domains with a zero-length or null MX record, but that must be set by the domain owner. http://www.postfix.org/postconf.5.html#reject_unknown_sender_domain http://www.postfix.org/postconf.5.html#reject_unknown_recipient_domain (Surprisingly, hotmal.com has a null MX, but gmail.co doesn't. Anyone here know someone at Google?;)) I suppose it would be possible for someone to operate a rhsbl listing domains that persistently don't receive mail. It's not clear the benefit would outweigh the effort... -- Noel Jones
