Unable to Send Mail to TalkTalk/Tiscali Recipients

[JCDeliverability]

Hi,

I'm a deliverability consultant and my customer is having sporadic issues sending to Tiscali & TalkTalk email addresses; they're occasionally receiving a TT406 bounce. SNDS score for their dedicated IP is consistently green, as is their domain/IP reputation in GPT. I've been reviewing the sends that bounce and see no issue with list targeting or the specific content in the mail.

I've been trying to track down a postmaster contact but I'm struggling to find an address. Please can a member of support get in contact with me so I can provide specifics of the IP/Sender?

Thanks in advance!

[IanHowe]

Thanks, Gondola.

Thanks for getting back so quickly and for the explanation of what's happening. I've noticed some spam coming through recently from Gmail addresses, so it's interesting to hear the background. I'll pass on your advice and hope that Gmail can start to get their act together.

Thanks again,

Ian

[Gondola]

Hi Ian

There's going to be a lot more users of Gmail that are going to be getting rejected by the TalkTalk Mail servers with a TT406 bounceback that indicates previous mail being sent by the same Gmail server IP address has been deemed as spam.  This is because Gmail are currently sending a lot of spam to TalkTalk customers.

TalkTalk don't do whitelisting because that would open the door to spammers. If TalkTalk whitelist one genuine user then they'd have to whitelist all genuine users to be fair and that would be a huge manual task to verify and list.

It's up to Gmail to improve their reputation by stopping spam at source.

Your client has two options:

1. Report the issue to Google / Gmail
   The last time this happened Gmail switched the sender IP address to a new one
   Doesn't stop the spam but allows a breathing space with a 'clean' IP address in use
2. Use a non Gmail address to communicate with you

[IanHowe]

I've just had a similar problem. A client I've dealt with for years has received that same message and TT406 error. He uses Gmail and hasn't had any problems with any other ISPs. He's asked if it's possible to whitelist him; would that help?

[Gondola]

TT406 is a rejection by the TalkTalk inbound mail server that indicates previous mail has been deemed as spam.

As the sending service IP address is not shared then it's likely that some TalkTalk Mail recipients have marked the mail as unwanted. This can happen particularly when an unsubscribe request did not appear to work / prompt removal of rejecting addresses didn't happen.  Or the content has at some time been fingerprinted as suspicious.

If the sending service IP address had been shared then some other client has been sending spam to TalkTalk Mail recipients.

Are there a range of sending IP addresses in use? Your report might suggest that one IP address has a poor reputation.