On 22.01.2026 at 06:57 Gregory Rocher via mailop wrote: > Le 21/01/2026 à 23:33, Andrew C Aitchison via mailop a écrit : >> No idea whether it is related but Linux web-browsers tell me that the >> certificate for download.microsoft.com is signed by an unknown issuer. >> It is possible their issues are wider than just email.
> Hi > On the download.microsoft.com certificate openssl sees a problem with the > chain yes >> [grocher:~] $ date >> jeudi 22 janvier 2026, 06:56:53 (UTC+0100) [grocher:~] $ openssl >> s_client -connect download.microsoft.com:443 >> CONNECTED(00000003) >> depth=0 C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = >> akamai.download.microsoft.com verify error:num=20:unable to get local >> issuer certificate verify return:1 >> depth=0 C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = >> akamai.download.microsoft.com verify error:num=21:unable to verify the >> first certificate verify return:1 >> depth=0 C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = >> akamai.download.microsoft.com verify return:1 >> --- >> Certificate chain >> 0 s:C = US, ST = WA, L = Redmond, O = Microsoft Corporation, CN = >> akamai.download.microsoft.com >> i:C = US, O = Microsoft Corporation, CN = Microsoft TLS G2 ECC CA OCSP 02 >> --- Yeah, it's a bit messy. The endpoints behind download.microsoft.com return different certificates and the ones issued on 2026-01-13 are lacking the certificate chain. If your client is not already in possession of the intermediates "Microsoft TLS G2 ECC CA OCSP 02" and "Microsoft TLS ECC Root G2" the verification will fail. But this is certainly unrelated to the SMTP errors. Guides from Al Iverson (https://www.spamresource.com/2020/08/help-im-blocked-at-microsoft-what-do-i.html) and Hetzner (https://docs.hetzner.com/robot/dedicated-server/troubleshooting/microsoft-blacklist/#olc-outlook-consumer) have been shared on this list in the past on how to solve that. In most cases it boils down to: 1. Open a ticket via the linked form 2. Wait 3. Escalate 4. Repeat steps 2. and 3. until the issue is solved -- 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
