Issue: Email reputation is quickly becoming a dominant facet effecting deliverability of email. SendGrid, among several, is an email service that offers features such as validation, analytics, and so on, and has other features to help improve your email reputation. In this example a server is using Exim with cPanel.
Solution: Configure Exim to use SendGrid (in a sense like a Smarthost).
Log into WHM and (in the left sidebar) navigate to:
Service Configuration >> Exim Configuration Manager >> Advanced Editor (tab)
Search for “Section: AUTH” (it may be empty) and enter the following:
[sourcecode language=”plain”]begin authenticators
driver = plaintext
public_name = LOGIN
client_send = : SendGridUsername : SendGridPassword[/sourcecode]
Note: Substitute SendGridUsername and SendGridPassword with your working SendGrid credentials. Also the “begin authenticators” directive should only be included in that box once.
Search for “Section: PREROUTERS” and enter the following:
send_via_sendgrid: driver = manualroute domains = ! +local_domains transport = sendgrid_smtp route_list = "* smtp.sendgrid.net::587 byname" host_find_failed = defer no_more
Search for “Section: TRANSPORTSTART” and enter the following:
sendgrid_smtp: driver = smtp hosts = smtp.sendgrid.net hosts_require_auth = <; $host_address hosts_require_tls = <; $host_address
Save the configuration (which will restart Exim).
Outbound email will now route through SendGrid.