black listing our mailserver

[samba.tounsi]

Hello everyone,
In our corporate webmail, certain destinations are prohibited to us: a message tells us that we are blacklisted.
However, when we approached our ISP, he told us that our problem is internal because our public IP address that he assigned to us is not blacklisted, but our domain name. The ISP is ready to change our public ip address, but that wouldn't solve the problem.
Please tell me what we could do.


thanks

[Admin]

I have not really seen many cases where a domain is blocked. What is the exact message you get? Generally it is IP addresses which are blocked. Use mxtoolbox.com to check whether your IP is on any blacklists, though it does not cover private blacklists.

[samba.tounsi]

Thank you for your reply,
When I check my IP address against MultiRBL.valli.org - Blacklist, Whitelist and FCrDNS check tool, just to make sure it is really not listed, I get the result attached as complete_IP_Check.png.



What do you think about this output?

Thank you in advance.

[Admin]

Your IP is not on any blacklists I can see, but your provider is. See https://www.uceprotect.net/en/index.php?m=3&s=5. So this may impact your deliverability. But you will need to check the actual bounce/error message.