How to change Server's Default Exim Mail IP?

You can follow these steps to change Exim Mail IP of a server.

1.Login to cPanel as root. Then,

2.Main >> Service Configuration >> Exim Configuration Manager
   Basic Editor  >> Domain and IPs
  change the following options as follows,
  Send mail from account’s dedicated IP address               off
  Reference /etc/mailhelo for outgoing SMTP HELO           on
  Reference /etc/mailips for outgoing SMTP connections    on

3.Login to server backend as root. Then,

4.Open /etc/mailhelo and add the following line in it.
  *: <server_hostname>

 Example:  *:

5.Open /etc/mailips and add the following lines in it.
  *: <new_IP>

 Example:  *:

1.You can also give separate mail IP for each domain and subdomain 
   Example: /etc/mailips ----> :
                   /etc/mailhelo---> :
2.To check whether the Mail IP changed or not, just send a mail and view the mail header. You can view the sender mail IP there.

Reference:- You can use the following cpanel doc for reference.