This topic

emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 14:09:34 GMT

Hi, first post here.

First a little rant, I've had to register under my partners surname as my own is rejected as containing unacceptable language (F-A-Gan)! unbelievable!

But to my main gripe, I was sending an email to the members of our small charity committee this morning (8 people, all on "domestic" email addresses) using Thunderbird and my own domestic btinternet address. The two gmail addresses both gave this response;

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

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 14:27:57 GMT

I should have added

What the heck does this all mean, and how do I resolve it?

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

licquorice — Mon, 15 Jan 2024 15:32:46 GMT

Are you using your own domain's server to send btinternet email?

BT's DMARC authentication is fine.

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 15:36:25 GMT

No, I'm a total numpty with this stuff so all settings (in Thunderbird and Btinternet) are default, so I assume the server is standard BT

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

licquorice — Mon, 15 Jan 2024 15:44:37 GMT

Is it just those 2 Gmail addresses or do all Gmail addresses give an error?

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 15:48:49 GMT

Hard to say, as these are the only 2 of my regular contacts who use gmail. Last month (last committee meeting) their addresses worked just fine, as do others on a music group I'm with

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

licquorice — Mon, 15 Jan 2024 15:59:46 GMT

Not sure where the fwd1.hosts.co.uk is coming from, there's nothing from Gmail. Are the recipients forwarding their Gmail to own domain addresses?

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 16:03:47 GMT

yes, they both have a private domain at me.uk, is this the issue? If so what can we do?

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

licquorice — Mon, 15 Jan 2024 16:09:02 GMT

They need to get their domain provider to configure their DMARC, SPF and DKIM settings correctly, but it all seems to be back to front as it is you sending not them.

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 16:15:58 GMT

I'll get onto Bob to check his end, once he finds a grandson to explain the request! I still don't understand why its happening unless he's clicked some "maximum security" setting.

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Les-Gibson — Mon, 15 Jan 2024 16:48:35 GMT

I suspect that gmail is seeing your attempt at sending bulk emails as Spam, hence the reason that they fail, can you send individual messages to both of those addresses ?

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

licquorice — Mon, 15 Jan 2024 16:54:21 GMT

No, its not that.

Its weird, it seems like a btinternet address is being sent using an own domain SMTP server, not entirely sure where Gmail comes in to the error.

But worth a try, if only to discover which of the 2 addresses is causing the problem.

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 16:54:35 GMT

1. I tried sending just to those two (partners with different roles), with the same result

2. In what sane universe is 8 recipients a bulk email?

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Les-Gibson — Mon, 15 Jan 2024 16:59:01 GMT

@Maartinf

Help prevent spoofing and spam with DMARC - Google Workspace Admin Help may help answer some of your questions

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Maartinf — Mon, 15 Jan 2024 17:05:47 GMT

Sorry, that doesn't help at all - I don't use gmail, or even understand what is being said. That looks like its set up for an an email administrator for an organisation, not a simple guy sat on a laptop trying to send a report on committee actions to other members of a small charity.

Re: emails to gmail addresses undeliverable due to DMARC Authentification issues

Les-Gibson — Mon, 15 Jan 2024 17:11:56 GMT

In message 2, you asked "What the heck does this all mean", that part at least is clearly explained on that linked page