Mail delivery failure

[malchr1s]

Sending out an email to several recipients receives the following error message from one of the recipients. Other gmail recipients receive email messages ok. Can you explain in easy terms what I need to do to allow my email to be sent to this particular recipient?

This is the mail system at host exch-smtp-out.livemail.co.uk.

I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can delete your own text from the attached returned message.

                   The mail system

<xxxxx@gmail.com>: host gmail-smtp-in.l.google.com[108.177.119.27] said:

    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. Please visit

    550-5.7.26  https://support.google.com/mail/answer/2451690 to learn about

    the 550 5.7.26 DMARC initiative.

    nb19-20020a1709071c9300b00946f79be789si4350101ejc.985 - gsmtp (in reply to

    end of DATA command)

<xxxxxxx@gmail.com>: host gmail-smtp-in.l.google.com[108.177.119.27]

    said: 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. Please

    visit 550-5.7.26  https://support.google.com/mail/answer/2451690 to learn

    about the 550 5.7.26 DMARC initiative.

    nb19-20020a1709071c9300b00946f79be789si4350101ejc.985 - gsmtp (in reply to

    end of DATA command)

Hoping you can help

Regards

Malc

[Gliwmaeden2]

@pipexdinosaur, please start your own thread. Staff just reply to the original poster when it affects particular accounts. 

You need to return to the message board and click on start a topic. 

Also complete your community forum profile details for TT staff to identify your account. Go via your avatar/name; settings. Add your landline number or My Account number in Personal Information. SAVE CHANGES. 

[pipexdinosaur]

I have a similar issue, emails being bounced back from gmail with a warning "550-5.7.26 This mail is unauthenticated, which poses a security risk" . Its been ongoing a few weeks....

[Ady-TalkTalk]

Hi Malc, please add the TalkTalk email address you're sending from to your community profile.

Ady