Moin, am 21.10.22 um 08:02 schrieb Johannes Posel:
Am 21.10.2022 um 04:01 schrieb Kai 'wusel' Siering via mailop <mailop@mailop.org>: I dont't talk about Reply-To; it's an irrelevant twist. The real world szenario is that some...@t-online.de mails to i...@verein.de ("verein" means association, club, …), verein.de does run it's own mailserver as it's cheaper than using some SP for it. verein.de runs basically default settings – which usually are good –, thus *not* blocking mails from @t-online.de, hence i...@verein.de receives the mail and reponds to it. *BÄM* 554.It would most probably not be a problem with verein.de, which most probably runs a website, and thus already has an imprint stating their board, their register number and court in addition to address and mail or telephone — as they are required by law. That is the trouble with examples.
Sorry, but you deviate from the facts: i...@verein.de is being harassed by t-online.de a) by delivering a message from one of it's users *although* t-online.de *knows* that the receipient cannot answer and b) by responding with 554 to the reply, which is now lost. Whether or not verein.de has a website is irrelevant. What *is* relevant though is that for every but one public mail service there would be no 554, and that one exemption is t-online.de. This should be reflected in MTA default configurations: mail exchange from and to @t-online.de has to be enabled manually as per t-online.de's policy. Someone mentioned that B2B mailservers might be configured "like t-online.de", that is only talking to whitelisted peers. Might be, but that's just another misleading example.
Consider T-Onlines move more like the overall accepted policy of not accepting mail from IPs that somehow have traces of residential in their PTR (cable, dialup etc.)?
No. As it's not relevant what your PTR says, you are always 554'd until you contact t...@rx.t-online.de. Add a second IP to your mail-out.fqdn? 50% 554's. As you put it: "That is the trouble with examples." ;-) Am 21.10.22 um 13:28 schrieb Gellner, Oliver via mailop:
Verein would still be impacted because having an imprint alone doesn't help. A mail operator of verein.de would still have to manually contact t-online.de to have their MTA IP addresses added to their whitelist. A distributed system like email does not work if everyone has to contact the operators of other MTAs over an out of band channel first before being able to send a message.
This. Of course one *can* do that, but than this should be properly reflected in MTA default configurations and even BCP documents. Even if it's just an odd mail provider from Germany, hence mostly irrelevant for the world at large. -kai _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
