I should say that I have found a tool at https://mxtoolbox.com/ and it says my ip address (18.104.22.168) is blacklisted. I don’t know how this has happened since I only set the mail server up over the last couple of days.
I have had the following response from 123-reg’s mail server:
This is the mail system at host oak.lampworx.co.uk.
I’m sorry to have to inform you that your message could not
be delivered to one or more recipients. It’s attached below.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
email@example.com: host mx0.123-reg.co.uk[22.214.171.124] said:
550-ATLAS(2503): 126.96.36.199 is blacklisted and not authenticated. Please
550-request delisting via the following link: 550
https://www.spamhaus.org/query/ip/188.8.131.52. (in reply to MAIL FROM
You’ll notice that the address that is blacklisted is not my ip address, but it belongs to BT.
The ‘delta101.co.uk’ is another domain of mine hosted on 123-reg’s server and that works fine.
If you go to spamhaus they say that BT operate a PBL and won’t send any email from an unauthorised server or a non btinternet.com email address. Could this be the problem?
The ‘lampworx.co.uk’ domain is parked on 123-reg’s servers and I have the MX record in their dns pointed to my server so they cannot block ports. However, BT are are my service providers and I have raised the issue with them. That could take a while as it has been escalated beyond ‘a broadband fault’.
My smtp server points to the following: mySMTP_Server 192.168.1.222
and the following ports are mapped to that ip address:
Protocol Port Range Translate To
TCP 80 80
TCP 443 443