How to whitelist IP addresses for email routing.
For two weeks now email I send out from my HostGator hosted email account gets rejected due to Cloudmark CSI-Global blacklisting. HostGator tech support said I needed to talk to my ISP tech support and have them whitelist the IP addresses with Cloudmark. The addresses I have had issues with so far are:
Some example error messages below showing the blacklisting:
host 188.8.131.52 Delay reason: SMTP error from remote mail server after end of data: 421 184.108.40.206 is listed on Cloudmark CSI-Global.
host 220.127.116.11 SMTP error from remote mail server after end of data: 421 18.104.22.168 is listed on Cloudmark CSI-Global.