I think you have no problem with your server, but you have to set your settings correct were you have registered your domain name.
Take a look at your MX records and the information you have from your ISP.
I think your error is there:
Preference Host Name IP Address TTL
0 mail.linuxgeek.net 68.15.17.xx 86400
10 home.cidhosting.com 66.126.84.xx 8640
An check on home.cidhosting.com tells me:
No connection could be made because the target machine actively refused it.
So if line 10 is not excepted it will never reach line 0, so it will never reach your mail.linuxgeek.net
To do further checks:
http://www.mxtoolbox.com/index.aspx