My domain is pointing to a remote mail server. How to configure the mail service on my server?
If your domain for example is pointed just via A record to your Server, you shall not be able to send mails from the servers because the MX records are pointed elsewhere. You can easily change that just by log in via SSH on your dedicated server and then open:
If the domain is listed here and remove it if it is. Next you should open
And add the domain here. Now you shall be able to send mails from the server with that domain