70447 DNS / Mail issue

I have a dedicated Linux server with Server Beach. I am running WHM 9.2.0 cPanel 9.3.0-R5 RedHat 9 - WHM X v3.1.0 I am having a problem sending emails from any domain. Through the original setup of the server,Server Beach suggessted not to use a domain that would be hosted on the box as a hostname. Well, my website is [login to view URL], and I wanted to host it there along with my customer sites, so I named the server (form an example) server1.osmn1.com. Well, that seemed to work for a while, sites are working and all that, but I constanlty get errors when Cron jobs run or what not trying to notify me. So I decided to register [login to view URL] and point the nameservers to [login to view URL], [login to view URL], and use my IP. Since then my email and FTP do not work? so I named the hostname to [login to view URL] hoping this would resolve the problem, and just deal with the server emails.. but it's still nt working.