On Thu, Aug 14, 2025 at 08:28:08AM +0100, Stuart Henderson via mailop wrote: > With some implemwntations it is possible to do this and accept mail from > conforming servers on the first delivery attempt (so not greylist-like > at all really in that sense), so you can do "early talker" (aka pregreet > delay) without the big problem greylisting has with retries from a > sending system that uses multiple exit IPs for retries of the same > email.
Yes, the multiple sender IP problem is the main downside of greylisting. You can to some extent mitigate by explicitly allowing whatever known-multiple domains publish in their SPF (see eg https://nxdomain.no/~peter/goodness_enumerated_by_robots.html or tracked https://nxdomain.no/~peter/goodness_enumerated_by_robots.html) but I have recently also seen such things as webshops that send their "confirm login" and "reset password" mail from hosts not listed in their SPF info. So yes, everything *does* have a strictly nonzero error/failure rate. - Peter -- Peter N. M. Hansteen, member of the first RFC 1149 implementation team https://bsdly.blogspot.com/ https://www.bsdly.net/ https://www.nuug.no/ "Remember to set the evil bit on all malicious network traffic" delilah spamd[29949]: 85.152.224.147: disconnected after 42673 seconds. _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
