Our IP address 553 5.3.0 flpd598 DNSBL:RBL 521< 184.108.40.206 >_is_blocked. For assistance forward this email to firstname.lastname@example.org has been blacklist apparently for no reason. I believe that your system may have falsely detected our IP range as being dynamic for sending emails but it is not. We have several customers that use their own servers to send email with, and their servers are dedicated to them and solely them. This IP listed here is the IP to one of our servers and is not in anyway at all being used for spam. We also do not under any circumstances change email sending IPs. We've tried to contact your spam team already and get no response. I respectfully ask that you remove the IP from your blacklist.
I'd also like to note that there is a long, a very long history of this occurring solely with ATT that the web hosting industry has years of complaining about to no avail. In our specific situation, if you run the IP you will see that it has a very high senderscore, has zero listings on blacklist, and has not caused issues. In fact, one of our primary IPs, 220.127.116.11 is ALSO blocked apparently for absolutely no reason. This is the IP to one of our primary servers that does not have or use mailing list, and has an extremely low volume of email. Please have our IPs removed from your blacklist