Many providers now block outbound connections on port 25, which means that a cPanel system would need to configure a Smarthost to allow for outbound emails to function. This resource covers how to set up a Smarthost using a common 3rd-party mail provider, MailJet.
MailJet has several plans, including a free tier that allows for up to 6000 monthly, and 200 daily emails to be sent.
The MailJet smarthost setup instructions are similar to the SendGrid smarthost setup instructions. The main difference with MailJet is that it uses "ROUTERSTART" instead of "PREROUTERS".
1. Sign up for MailJet
2. Log in to WHM, and navigate to WHM > Service Configuration > Exim Configuration Manager > Advanced Editor. On this page, search for "Section: AUTH". In the text box, input the following:
driver = plaintext
public_name = LOGIN
client_send = : USERNAME : PASSWORD
Your login information can be found within the MailJet interface.
3. Next, go to the "Section: ROUTERSTART" section, and input the following:
driver = manualroute
domains = ! +local_domains
transport = mailjet_smtp
route_list = * in-v3.mailjet.com
4. Then go to the "Section: TRANSPORTSTART" section. Input the following into the text box:
driver = smtp
port = 587
hosts = in-v3.mailjet.com
hosts_require_auth = in-v3.mailjet.com
5. Go to the bottom of the page and click, "Save". The changes will get added to the Exim configuration and will automatically restart the Exim service.
6. Try sending a test email using one of the Webmail applications. If the email does not leave the server, you must examine the /var/log/exim_mainlog file to determine the cause of the issue.
This guide is a task intended for system administrators. cPanel's Technical Analysts cannot provide assistance in configuring a server's smarthost setup.
Configuring a smarthost will cause all outbound emails to go through the configured provider. The scope of this document does not cover how to configure a subset of domains to go through a smarthost; this must be configured by the system administrator of the server.