on 18-10-2021 09:33 AM
I am an email marketer and noticed that a number of talktalk.net and tiscali.co.uk addresses are hard bouncing. I've looked into the records of these contacts and they are all consenting subscribers and have all engaged with emails previously (and recently). It's not affecting all talktalk/tiscali addresses just some of them, approx 10-15 for each campaign.
Our ESP support say that the domains aren't blacklisted and they are getting a recipient undeliverable (TT512) error for these specific addresses.
Any ideas why this is happening?
on 19-10-2021 12:25 PM
Hi des_de_mona, I can help with this. I've sent you a personal message to obtain more information and provide you with some.
on 19-10-2021 10:17 AM
What can happen is that some recipient addresses in a distribution list are not valid and a TT506 error is bounced back. Heads up that TalkTalk Mail users may delete email addresses when they're no longer TalkTalk Consumer customers.
If the originator does not remove these addresses from the distribution list and the ESP continues to send to non-valid addresses then rate-limiting will kick in and a TT512 error is bounced back. The email is undeliverable, in this specific case, not because all addresses are unavailable for delivery but because the system is not accepting them all for delivery.
The fix is to clean the distribution list and send in smaller batches. Test by selecting one of the 'failed' addresses, checking with an address verifier that the address is active and sending a test email just to that address.