cPanel/WHM: Fix for 550 Access denied - Invalid HELO name

Big Dan

EQ Forum Moderator
I have a CentOS VPS server running WHM/cPanel. Lately, I haven't been receiving email notifications from my forum hosted on this server. Long story short, I looked at exim log and seen every notification going to me had the following error:

SMTP error from remote mail server after MAIL FROM:<odjt@mixmaster> SIZE=8943: host []: 550 Access denied - Invalid HELO name (See RFC2821

The problem is my host name wasn't set as a fully qualified domain name. Simply changing the host name to instead of mixmaster fixed the issue.

Hope it helps anyone who has come across the same issue.