on 19-04-2022 04:29 PM
I work for a UK Publishing company whereby we have many brands on our Email Newsletter system, with our users who have opted in, recieve daily news newsletters from us. We're encountering a big issues with our newsletters NOT reaching a chunk of Talktalk.net users (all using @ talktalk.net email addresses) that have signed up to our newsletters.
We've looked into it our side and with our Email Service Provider, and a lot of the reasons for them not getting to our users is your email system is due to the following recieved error:
This means that our email server tried to send the email to the user's email server (TalkTalk) but we were rejected due to the TalkTalk server being unable to locate the email address as an active email address - Oranother possibility is due to server-level security filters beyond our control on your end. However, we've had the same people complain to us via the very same email addresses that apparently don't exist. Granted, these go into a different email service, but this does lead me to believe there is an issue on TalkTalk's end, as our ESP has been getting all these responses back from your own email service as UNKNOWN_USER_BOUNCE.
Who can I contact please to get this looked into? I have estimated around 4k contacts we have which are @ talktalk.net email addresses appear to be having this issue. If it was just the odd one or two, I would assume it was down to user error or the user blocking the emails - but this doesn't appear to be the case.
on 22-04-2022 07:04 AM
on 21-04-2022 01:57 PM
on 21-04-2022 07:33 AM
Hi robbutler, I've sent you a personal message. It includes an email address for you to send the same information to. The incidents team should then pick this up for you.
20-04-2022 02:21 PM - edited 20-04-2022 02:56 PM
@Ady-TalkTalk- I've added the sender address for lep.co.uk there, but to give context, we have around 60odd news brands, all on different domains (All setup on HubSpot, with valid SPFs, DKIMs and DMARC policies in place). I'll compile them all and also add in there a bit later today. They tend to follow the same pattern for newsletters, but we do also have some others that come from HubSpot as the brands which may also help investigations.
@Gondola- Interesting - I didn't know that. Thank you for that information.
Edit: @Ady-TalkTalk - have added a bunch of our brands email send from names in that profile section for you.
on 20-04-2022 01:32 PM
I've asked the business to comfirm if we've made changes to cloudmark that have led to this issue.
on 20-04-2022 01:00 PM
Hi, just looked at your delivery report. The TT512 error code is used when a mailbox is unavailable and also when users have marked mail as spam instead of unsubscribing. So, my initial thinking is that CloudMark is fingerprinting mail as spam. i.e. it's specific mailboxes that are blocking (and hopefully you're cleaning the mail list of those) and because of the user blocking, CloudMark uses the fingerprint characteristics of the blocked mail to reject delivery to mailboxes that would be willing recipients for the newsletter mail.
I think what's required in this case is for TalkTalk to 'reset' CloudMark so it ignores the past history and starts afresh. But that's just my opinion, it's up to TalkTalk to make an appropriate decision.
on 20-04-2022 12:44 PM
Hi robbutler, please add the sending address to the private notes in your community profile.
on 20-04-2022 12:38 PM
This screenshot is taken from a user who bounced with Unknown User and we have since been able to successfully deliver emails to after forcing a resend via HubSpots manual unbounce feature (this was after customers started to make us aware of issues)
Some other emails also state:
Hard bounced (Unknown user)
Recipient's email address is invalid, misspelled, or blocking incoming email
UNKNOWN_USER 550 5.1.1 WGsjnpHmKCNsY Recipient Undeliverable (TT512)
Same recipient yesterday, all fine:
on 20-04-2022 12:36 PM
on 20-04-2022 11:01 AM
Found out more about our DMARC policies, it's set to quarantine, so any would go into a users SPAM if for whatever reason some validation failed. It's not set to Reject. I'm still waiting to see if I can get more detailed logs and I've managed to coerce HubSpot to look into things more their side.
If anyone would be so kind as to register with one of our websites below and sign up to a newsletter - that would be great.
Please tick the "regular news stories" newsletter opt in on sign up.
If you could then send me your email address via a PM I can check things on our side. Ideally, it would be good if we can have our newsletters attempt to send for a couple of weeks to see if the issue occurs (you can also opt out at any time and I am also happy to remove your account fully once we're done). Unfortunately there doesn't seem to be any pattern to the issue, but many of our talktalk users begin recieving emails and then suddenly, randomly, "Unknown Sender" is recieve and our emails start failing.
With regards to the HubSpot community link, we regullary clean our data and actual fake/incorrect emails are routinely removed from sends. The main thing is that users TalkTalk have said are unknown, when we manually force the sends to those users (i.e telling HS to unbounce to try again), they get the emails fine with no errors for a bit.
on 20-04-2022 09:09 AM
Hi robbutler, Gondola will put you on the right path. Please let us know how you get on.
on 19-04-2022 06:55 PM
on 19-04-2022 06:16 PM
More detail in the sender bounceback logs would be good. Please ask some users to register here in Community and request help with the deliverability of your mailings to their email address. TalkTalk Support would need to tie a customer's email address to a failed send of one of your emails in order to look at the mailbox over a given timeframe for a given sender to see if the mail was accepted/rejected or deferred/spam tagged.
on 19-04-2022 05:24 PM
I've put in the request to see if I can get more detailed logs.
RE: the setup of our sending domains etc, we have setup and verified DKIM, SPF (which uses a domain which dynamically updates any IP under it for sending as well as some IPs) and I bleieve our domains are also setup with a DMARC policy.
We use HubSpot as our Newsletter ESP, and delverability is generally really high with these to all email providers. It's this big dip that appears to be occuring with TalkTalk that's brought me here, as it's occuring a lot more frequently it seems. Even newly registered users who get the first few newsletters suddenly have been coming back as Unkown Users from TalkTalk, although they are clearly real emails as they contact us to complain from them.
Unfortunately, I can't share our customers email addresses - even to support, without their consent. However, I am hoping that I can provide enough information for a look into it.
19-04-2022 04:48 PM - edited 19-04-2022 04:49 PM
A bit more detail on the bounceback error message would help to identify the issue. ESMTP code and TT error code would be useful. What's the originating domain and the mail sending service? Does the SPF for the domain specify the IP addresses / ranges in use by the sending service? Is there a DMARC policy in place?
The senders could be getting totally rejected because in the mail distribution lists there are some non-existent addresses. If those aren't removed then the senders are treated in the same way as spammers.
If you have an example of a 'valid' talktalk.net email address and the last time of sending / rejection, so long as that's in the last week and not earlier, then put that recipient email address, the originating email address and time of sending, in your Community profile Private Notes box and TalkTalk Support will check to see the reason for rejection.