on 10-03-2021 03:24 PM
I have a new issue which started, as far as I know, last Saturday, 6th March.
I regularly send out an email newsletter by email to a distribution list that has been in use for many months. On Saturday 6th March I sent this as usual at 13:06 and all seemed well.
On Sunday 7th at 09:21 I received a burst of 19 emails from email@example.com advising that the delivery of my outgoing email of the previous day had been aborted after 24.9 hours because the message was undeliverable due to maximum retry queue age reached. Inspection of these 19 bounce messages showed that in every case the recipient was a btinternet.com mailbox user.
Subsequent testing with a friend who is a btinternet.com user showed that he was not receiving my mails, where if I logged in to my google account and sent him a mail from there, he received it fine.
The problem is still currently ongoing. I am not sure where the problem is:
1) a problem with BT not receiving mails from certain mail boxes or domains;
2) a problem with TalkTalk that is for some reason not sending out mails to btinternte.com domain users. I am using the smtp.talktalk.net server for outgoing mail.
I have no issue sending mails to any other addresses.
Does anybody have any ideas as to the likely cause of the problem and how to resolve it?
on 11-03-2021 10:27 AM
on 11-03-2021 09:56 AM
Thanks yes we now have this sorted.
Our DNS record has been amended so that the SPF record now covers the talktlk.net mail cluster and not just an individual server. We have also added DKIM signing and a DMARC policy so we now have full authentication and SSL signature on mail headers. All now talking happily to btinternet.com.
on 11-03-2021 07:56 AM
Hi MichaelFLong, it looks like Gondola has got you covered with this.
Please let us know how you get on.
on 10-03-2021 03:53 PM
I've just successfully sent a message to a BT Mail email address so that suggests there's no block on accepting mail from the TalkTalk mail servers.
So either the BT spam protection is detecting potential spam or virus content or your public IP address or email address is marked as a spam sender. It's possible that the mail has been deferred for scanning and that's just timed out.
The BT Mail platform requires mail to be fully authenticated and using secure SSL/TLS encryption to be passed to recipient mailboxes without being automatically flagged for scanning.
By using the TalkTalk outgoing SMTP server for your personal domain mail, if that's what you're currently doing, you're not getting the benefit of full authentication, so inevitably, receiving mail services are going to flag this up.
We have covered this before.
To prove that you can send mail to the BT Mail platform just use your TalkTalk email address either from webmail or using the recommended email settings with an email client supporting TLS1.2 or better. Email settings - IMAP & POP3