Hello,
It's not resolves the issue. We just FLAG on the following RBL list
Spamcop (http://www.spamcop.net)
Spamhaus (http://www.spamhaus.org)
The CBL Composite Blocking List (http://cbl.abuseat.org)
We used CENTOS 6.10 64 bit, Cpanel v80.0.20 and MagicSpam v2.1-11.2

Hello, Our customer missing some mail because of the error bellow, I added the email sender and Server IP to the whitelist but still get the same error, then I disabled MagicSpam and the problem was solved. I want to know the reason why and how to fix it permanently 2019-10-22 13:48:31.835 [16927] H...