We have an in-house smtp server which connects to the Internet through a Virgin Media business connection with fixed IP and reverse DNS. The IP address is not blacklisted on any of the public blacklists (checked at mxtoolbox.com) - but it appears to be blacklisted on the TalkTalk servers. When we try to email TalkTalk email addresses, our connection is refused - this is an excerpt from the logs at our end:
2020-02-11 10:26:33 1j1SkN-0003K1-LY H=mx.talktalk.net [184.108.40.206]: SMTP error from remote mail server after initial connection: 554 cm8nec mx.talktalk.net 1SkSjLYW6lCnh IP Blacklisted (TT103)
Our IP is 220.127.116.11
Does TalkTalk have a procedure or an online form to apply for the IP to be delisted? Any suggestions much appreciated.
I've alerted the TalkTalk team and they'll pick this topic up from Monday onwards.
TalkTalk don't do whitelisting but they may be willing to see why the blocking is in place and may clear the current block.
The bounceback report indicates that the mail sender is being blocked at a network level. The likely reason for this would be that too many mailboxes are being sent to that have marked the mails as spam. Recipients usually unsubscribe if senders make it easy to unsubscribe and quality senders immediately remove those addresses from their mail lists to prevent the spam blocking from being triggered.
I'd suggest you take the weekend to clean your mail lists to remove all unsubscribe requests and all unsolicited sending before you start sending again. A temporary clear of the IP block will rapidly get auto-set again if the send lists include non existent mailboxes or too many mailboxes marking mail as spam.
Thank you kindly for the reply and for contacting the TalkTalk team regarding this issue. Regarding your suggestions, it seems unlikely this has happened because our emails are marked as spam by TalkTalk users, as we email TalkTalk users extremely rarely - I think there have been 3 emails to TalkTalk addresses in the last 1.5 months since we've started to use this IP address. Also, we don't run a mailing list or any type of email marketing activity from this server or IP address.
Thanks again for your help.
In the circumstances you describe and if in the 6 weeks or so you've been using the allocated Virgin Media IP address it's always experienced the IP blocked error then it's most likely that your business has been given an IP address previously used to spam TalkTalk mailboxes.
I guess that could be a possibility - although if spamming activity would have been connected to this IP address in the past, I would have expected it to be blacklisted at other online blacklists as well - such as Spamhaus for example - not just with TalkTalk. If the previous users of this IP were somehow sending out spam (or allowing spam to be sent out), I don't think they would have only targeted TalkTalk addresses - I should think. It would be useful to see if TalkTalk staff can actually take a look at the situation and come back with a definite answer as to the causes we are being blocked - and of course, unblock the IP if possible.
Thank you again