I've been trying to track down this problem for months with no luck.

I've had clients tell me people are sending them email that they don't get. I've checked DNS records, A records, MX records, hostnames all with no luck.

Keep in mind all domains on my server can send and recieve email. It's just not all email is getting delivered to them.

Then today I sent myself an email from one email address to another email address ON THE SAME DOMAIN and it never came through!

It is becoming very frustrating. If no one here has any suggestions as to what is wrong, then how about suggestions for a professional email support tech?

FYI, my cp is Cpanel.

Thanks.