One of the users on my server (184.108.40.206) is having trouble sending email to any Verizon accounts. It looks like my server has been blacklisted by them for some reason. The message in the email is:
yAAAn@verizon...net SMTP error from remote mail server after initial connection: host relay.verizon.net [220.127.116.11]: 571 Email from 18.104.22.168 is currently blocked by Verizon Online's anti-spam system. The email sender or Email Service Provider may visithttp://www.verizon.net/whitelist and request removal of the block. 110510
There's no unusual levels of mail activity coming from my server, and I've checked all the blacklist sites and the IP does not appear there.
I used the online white request on Verizon's site, and I got this message:
After investigation, Verizon Online Security has determined that e-mail from your IP address will not be allowed access to the Verizon Online e-mail domain due to one or more of the following reasons:
Your IP has been blocked because of spam issues or because your ISP indicates that it is dynamically assigned
No Reverse Hostname associated with your IP address.
As far as I can see this is rubbish... or am I looking in the wrong places?
What other information do I need to be able to diagnose this?
I'm happy to make changes if necessary, but I've no idea where to go next.
EDIT: Might be worth noting that I've tried the removal request 4 times over two months. Same result each time.