We recently installed a Barracuda firewall and accidentally left “Proxy” on. This caused our IP to used as a spam relay which got our IP put on a blacklist. A trace route from our server to mtb.com showed the packets getting to MTB.com and stopping. We assumed it was MTB.com blocking the ip.
MTB said they get their blacklist for outside sources. They directed me to the following site were I was able to submit a request to get the IP off of the blacklist.
I could see that the IP was showing as suspect. I clicked on the “IP Reputation” and submitted the IP for review. I knew the proxy issue was resolved the IP should be cleared. This didn’t resolve the issue.
I discovered Barracuda has their own IP blocked. This showed our IP as not having a “poor” reputation.
Do more searching brought me to this page.
There were two sites that had our IP listed. When I tried to go to mailhosts.org I get an error saying that domain is available. Blacklisted with no way to get it removed.
Looking into alternative fixes.
I hope this helps someone else out there…