Dnia 12.04.2022 o godz. 15:03:40 Richard Rasker pisze: > > Sorry, I wasn't being clear here. What I mean to ask is if (and how) > using a mail relay for sending mail could solve the problem that at > the receiving end, reverse DNS does not match the originating > domain.
Reverse DNS doesn't have to match the originating domain. But it has to be consistent (ie. IP address -> PTR name -> the same IP address) and it has to be "non-generic", ie. "smtp.xs4all.nl" is good, while "195-121-65-191.dc.kpn.net" is not, as it seems too generic and many mailservers will reject such name. (Also, as someone noted, IP address 195.121.65.191 is included in SORBS Dynamic IP Addresses blacklist, so mail from this address will be rejected by most systems anyway) If the mail relay's *outgoing* IP address (note: we don't know the actual *outgoing* IP address that smtp.xs4all.nl uses, we know only the incoming address used to submit mail) has a non-generic and properly resolving PTR hostname, using a relay should solve your problem. However, while mail relay's PTR name doesn't have to match the originating domain, its IP address (the outgoing one) should be included in SPF record for the originating domain, if you do use SPF. -- Regards, Jaroslaw Rafa r...@rafa.eu.org -- "In a million years, when kids go to school, they're gonna know: once there was a Hushpuppy, and she lived with her daddy in the Bathtub."
