Introduction
If you want or need to setup your mailserver to send all outgoing mail to a specific server which will handle the delivery to the recipients you need to setup a SMTP relay or smarthost.
Prerequisites
- You need to know the hostname of the SMTP server which is going to relay the mail for your mailserver, which is smtprelay.snel.com in our case
- This article assumes that no authentication is necessary on the SMTP relay server
- This article is written for cPanel with Exim
- You need to have the login details of WHM ready
Step 1) Login on WHM
Go to https://x.x.x.x:2087 (replace x.x.x.x with the IP address of your server).
Step 2) Configure the MTA
Within WHM navigate to: Main > Service Configuration > Exim Configuration Editor, click on the Advanced Editor button and search on the page for "Section: POSTMAILCOUNT" and add the following:
smart_route: driver = manualroute domains = ! +local_domains ignore_target_hosts = 127.0.0.0/8 transport = remote_smtp route_list = * (your ip)::587 no_more
If "Section: POSTMAILCOUNT" is not available proceed to step 3, otherwise proceed to step 4.
Step 3) ONLY IF "Section: POSTMAILCOUNT" is not available
On the same page search for "Section: ROUTERSTART" and add the following:
smart_route: driver = manualroute domains = ! +local_domains ignore_target_hosts = 127.0.0.0/8 transport = remote_smtp route_list = * (your ip)::587 no_more
Step 4) Save changes
Click on the "Save" button on the bottom of the page to save changes and restart the mailserver to apply the newe configuration.