If you wish to just point mail to another domain do the following:
1. Log into your Cpanel.
2. Click MAIL.
3. Click "Modify Mail Exchanger (MX Entry)."
4. Put in mail.thedomainname.com of the domain you wish for it to go to.
Pointing your mail to your own mail server:
If you have your own exchange or other external mail server and you want to point the
mail to the IP address of that server you will need to open a ticket and make
your request and include your IP address. This information will not be taken over
the phone. You must open a ticket here.
1. Log into your WHM
2. Click edit DNS zone.
3. Pick the domain you wish to edit.
4. Change the MX from domain.com to mail.domain.com.
5. mail.domain.com should have the A entry of the external mail server IP address.
Note: If you ever send mail from any sites that's on the same server where your site
is hosted your external mail server will not receive the mail. The reason for this is
that a server will always try to send locally before it tries what the actual DNS
zone points to. The way to fix this is to open a ticket here (hosting support)
and in the body of the
"Please remove my domain ****.com from /etc/localdomains and
add it to /etc/remotedomains".
Only we are able to make this change for you. After the change is completed,
this problem should be fixed.