So these past two months multiple IP addresses have been being blacklisted on our WHM server resulting in users not being able to connect to emails. I had to keep contacting our host, HostGator and have them whitelist the IP addresses for me. Today it happened again at a different IP address and finally I asked HostGator if this is something I can resolve myself. Lo and behold this is something I could’ve done myself.

In cPanel’s WHM (Web Host Manager) there’s this thing called cPHulk (I lol’ed at this name at first) and from here you can edit IP addresses on the blacklist and whitelist.

http://docs.cpanel.net/twiki/bin/view/11_30/WHMDocs/CPHulk

Oh and as for why these IP addresses are being black listed the guy I chatted with said “Basically too many login attempts from the same ip will trigger a block.”