topic Re: DMARC in Email

DMARC

djburge1 — Sun, 05 Jan 2025 13:41:18 GMT

Emails keep bouncing back with the following message

SMTP error from remote mail server after end of data:
   550-5.7.26 Unauthenticated email from talktalk.net is not accepted due to
   550-5.7.26 domain's DMARC policy. Please contact the administrator of
   550-5.7.26 talktalk.net domain if this was a legitimate mail. To learn about
   550-5.7.26 the DMARC i

How do I set this up or can talktalk do this for me.

Re: DMARC

mbsharp — Sun, 05 Jan 2025 15:15:47 GMT

DMARC is part of a verification system for traffic between email servers. As such it is not something personal to you or which you can set up. If you look at other posts in this section you will see that loads of people have the same problem because the reputation of TalkTalk email servers has been trashed and multiple other email providers will not accept anything from TalkTalk. You can receive but not send. Maybe some time in the distant future TalkTalk will sort this out, but I wouldn't hold your breath. Meanwhile, get yourself a Gmail account.

Re: DMARC

djburge1 — Sun, 05 Jan 2025 15:19:09 GMT

Thank you for your reply . Much appreciated

Re: DMARC

jbuchanangb — Tue, 07 Jan 2025 11:50:02 GMT

It is a bit harsh to say that TalkTalk's mail reputation has been trashed. I experience the error description which you have quoted in one particular set of circumstances, when I send from a TalkTalk address to an email forwarding service, which then tries to send the item on to the real destination email service. That forwarding action triggers the DMARC error because the recipient service finds something not to like about my email message coming via a forwarding service. Oddly it only happens for a specific addressee when they are one of a list of addressees, not a sole addressee. I have reported in the forum, and effectively had to learn to live with it. See https://community.talktalk.co.uk/t5/Email/Delivery-failed-to-Gmail-address-via-an-alias/td-p/3080824

Re: DMARC

Ady-TalkTalk — Wed, 08 Jan 2025 14:09:23 GMT

OpenXchange have repeatedly advised that this only affects mail that's been forwarded. Any mail sent direct works normally.

Ady

Re: DMARC

jbuchanangb — Wed, 08 Jan 2025 14:47:17 GMT

I added my comment to help @djburge1 know that he is not alone. In my example which you helped me with earlier, the behaviour is complicated in that when using the forwarding service to a sole addressee, Gmail does not refuse the item forwarded from TalkTalk via IONOS (kundenserver.de). Mysteriously when the same addressee appears in a list of addressees, Gmail spots something it doesn't like and rejects it. I had another instance this week. My workaround is to resend the item to the failed addressee alone.

Re: DMARC

Ady-TalkTalk — Fri, 10 Jan 2025 08:36:52 GMT

All I can tell you is that I keep sending this back to the incident team who raise it with OpenXchange and in all circumstances OX tell us that its mail forwarding and the dmarc failure is due to that.

Ady