> On 14.02.2025 at 20:48 Richard Laager via mailop wrote: > > On 2025-02-13 16:54, Mike Hammett via mailop wrote: >> I'm trying to send an email to a well-known mailing list (voiceops). My mail >> server (Proxmox Mail Gateway) seems to be skipping over the server at >> preference 0 and is trying to send to preference 10. My issue is that the >> mail server at preference 0 has both IPv4 and IPv6 addresses, but the one at >> preference 10 only has an IPv6. I am IPv4-only, so we can't communicate. >> I already have a relationship with Jared, so I can work out the technical >> aspects of his free and appreciated service. I'm trying to figure out why I >> would have skipped over the supposedly preferred server to talk to the less >> preferred server. > > I could change that 0 to some other value to see if that matters. (I do have > the voiceops.org registrant's permission to do so.) My _personal_ feeling is > that if we are going to do that, before doing so, it would be nice to have > solid proof that your mail server got the right DNS records. Because if > Postfix is skipping a 0 MX, that seems like a bug, and having solid evidence > of it would be helpful.
I haven’t looked at the source code but I doubt that Proxmox modified Postfix in a way that broke certain MX lookups. I suspect the problem is either caused by a misconfiguration as mentioned by Viktor or by a different system like: - an issue with the DNS resolver being used - a routing problem to the MX IPv4 address - a device which blocks the connection - something that modifies or mangles the DNS responses Did you check if you can manually look up the domains MX entries and their IP addresses from the MTA server? Are the results identical to the responses from other DNS servers? Is it possible to initiate a telnet connection to that IP address on port 25 and talk with the MX server? — BR Oliver ________________________________ dmTECH GmbH Am dm-Platz 1, 76227 Karlsruhe * Postfach 10 02 34, 76232 Karlsruhe Telefon 0721 5592-2500 Telefax 0721 5592-2777 [email protected]<mailto:[email protected]> * www.dmTECH.de<http://www.dmtech.de> GmbH: Sitz Karlsruhe, Registergericht Mannheim, HRB 104927 Geschäftsführer: Christoph Werner, Martin Dallmeier, Roman Melcher ________________________________ Datenschutzrechtliche Informationen Wenn Sie mit uns in Kontakt treten, beispielsweise wenn Sie an unser ServiceCenter Fragen haben, bei uns einkaufen oder unser dialogicum in Karlsruhe besuchen, mit uns in einer geschäftlichen Verbindung stehen oder sich bei uns bewerben, verarbeiten wir personenbezogene Daten. Informationen unter anderem zu den konkreten Datenverarbeitungen, Löschfristen, Ihren Rechten sowie die Kontaktdaten unserer Datenschutzbeauftragten finden Sie hier<https://www.dm.de/datenschutzerklaerung-kommunikation-mit-externen-493832>. _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
