Incoming Emails to @ntlworld.com Addresses Blocked

[robinwilson16]

Hello

I run an email server which is not blacklisted by anyone (mail.robindigital.co.uk @ [IP removed] ) yet emails sent to @ntlworld.com addresses are always blocked.

Emails to all other domains work without issue and the issue seems specific to @ntlworld.com

I have looked to see if there is a de-listing process but cannot find one.

Please can someone advise how this can be addressed.

Thanks

Robin

[robinwilson16]

Thanks ravenstar68

I have contacted TalkTalk Business and asked them to add a reverse lookup record that resolves to mail.robindigital.co.uk.

Hopefully they will be able to add it and then hopefully it should resolve this.

It's strange it only affects VM. They must be stricter than the rest.

Robin

[ravenstar68]

I do know that it's good practice for email servers to have the correct reverse DNS, definitely shouldn't go back to a generic hostname.

I host via a VPN on OVH and before that with 1&1 Ionos, both of those support setting your reverse DNS.

[ravenstar68]

I meant VPS, not VPN - doh

[ravenstar68]

@robinwilson16 I see your reverse DNS has been changed.  Are you still getting bounces?

Tim

[ravenstar68]

@robinwilson16 

Is mail reaching the previously blocked addresses now?  I can see the reverse DNS has been set.

Tim

[robinwilson16]

@ravenstar68

Sorry for the delay in responding.

Thanks, I think that has done the job although I have asked a few times for the person who reported the issue to confirm it is resolved and I do not have anyone with those domains I can email so I believe it to be resolved as they are not complaining so hopefully there will be no more issues.

Thanks again for your help.

Robin

[ravenstar68]

If you are running the mail servers and you've made sends to the affected addresses, you should be able to check your mail server logs to confirm delivery.

[robinwilson16]

Yes thanks I will check through the log. I split them up between domains so it shouldn't be too hard to find.

[ravenstar68]

Assuming a linux/unix server and you've got the ability to ssh to the server just use cat <path to log file> | grep mx.tb.ukmail.iss.as9143.net.

That's the mail exchanger used for all 4 Virgin Media domains.

Tim

[RMTN]

Hello - I am having the same issue, and our reverse lookup record does resolve to mail.ourdomain.com so not sure why we are receiving the error message. Emails that were making it through to a @ntlworld.com have suddenly stopped working and we receive the following error message:

[theperson]@ntlworld.com: host mxin10.virginmedia.com[84.116.6.18] refused
to talk to me: 421 EHLO MXIN201 Your HELO/EHLO ln15.myplesk.cc is not
matching your DNS configuration mail.ourdomain.com. 

Using https://mxtoolbox.com/ I can see this is not the case, everything is resolving correctly, so unsure why I am receiving these error messages? Our hosting provider is also stumped. I received the same message when emailing a @virginmedia.com address. This is a new issue and the @ntlworld.com email address we are having the problem with we have been emailing for years. We are a business and don't do mail outs, simply use email to respond to customer enquiries. Any help would be appreciated - thank you!