Hello, this is VC Computer Team.
Recently we noticed that we couldn't send messages from our servers to email relays running Symantec products. Many connection attempts were rejected with the following response:
I checked our network against
https://ipremoval.sms.symantec.com/ and indeed found that some IPs have a negative reputation on Symantec RBL. The explanation is as follows.
IP 58.224.116.252 has a bad reputation.
Security measures against in-server spam and Rdns processing have also been completed, so we request BL release.