MyPostOffice/Shell Energy/Zimbra - Undelivered mail errors

legion1 — Sat, 06 Jun 2026 14:09:53 GMT

I am receiving bounce backs from Microsoft addresses in the last 48hrs.

I log in to webmail via https://webmail.shellenergy.co.uk/ which appears to use the Zimbra client.

The error links to this article from Microsoft, suggesting whoever manages the Zimbra implementation needs to fix some configuration to meet Microsoft's standards:

https://support.microsoft.com/en-gb/topic/fix-ndr-error-550-5-7-515-in-outlook-com-34cfe8f8-6fbf-457e-9e8b-9e4dbaf4e0ef

Is anyone else experiencing this, is there anything I can fix myself - or is there a specific address or department that I can raise this to?

Re: MyPostOffice/Shell Energy/Zimbra - Undelivered mail errors

fr8ys — Sat, 06 Jun 2026 14:29:31 GMT

Are you a TalkTalk broadband customer?

If not, have you received any emails requesting you subscribe to Everymail?

If so, ditto?

Of so, have you subscribed?

If still a broadband customer and you've received an email, Please see here for more details and the action you need to take depending on your circumstances.
https://community.talktalk.co.uk/t5/Email/Everymail-transition/td-p/3148465

If you are not a current customer and you've subscribed to Everymail, you need to contact them for support.

You could try turning your ONT and / or Router of for 30 minutes and trying again.

Failing the above, there is no staff presence here anymore and you will need to contact TalkTalk direct. Please see my signature for info.

Thank you

topic MyPostOffice/Shell Energy/Zimbra - Undelivered mail errors in Email

MyPostOffice/Shell Energy/Zimbra - Undelivered mail errors

Re: MyPostOffice/Shell Energy/Zimbra - Undelivered mail errors