On 2026/08/10 17:34, Peter N. M. Hansteen via mailop wrote: > On Mon, Aug 10, 2026 at 02:19:43PM +0200, Boris Mutina via mailop wrote: > > The provider recommends "adjusting anti-spam/greylisting configuration to > > properly handle messages sent from rotating IP addresses". And I have no > > clue what does he mean by that.
Generally this is "use a greylisting implementation which masks on /24 for v4 / /64 for v6". Sometimes using dnswl.org to exempt from greylisting is good enough, but it doesn't cover all senders that need it. > Sites with numerous outbound SMTP servers and non-sticky retry is a known > problem versus greylisting. One reasonable approach is to more or less trust > that the hosts listed in the SPF record for the domains you or your users > need to interact with are in fact legitimate. That works sometimes, but figuring out which domains you need to do it for it is a real pain, and some places use SPF macros such that you need to do a live DNS lookup using the actual sender's IP in order to determine whether it's permitted or not. _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
