Configuring Exim with cPanel and WHM for Mail Assure mail routing

The following instructions describe how to:

  • Restrict incoming delivery to Mail Assure only
  • Disable catchall behaviour
  • Route outgoing mail through Mail Assure



As the root user:

  1. Navigate to Service configuration > Exim Configuration Manager
  2. Set Access lists to Only-verify-recipient
  3. Configure this to contain:
  4. In the Service configuration > Exim Configuration Manager > ACL options set:
    • Ratelimit suspicious SMTP servers to False
    • Ratelimit incoming connections with only failed recipients to False
  5. In Server configuration > Tweak settings > Mail set:
    • Email delivery retry time to 5 minutes
    • Initial default/catch-all forwarder destination to Fail
    • Enable BoxTrapper spam trap to Off
    • Enable Apache SpamAssassin™ spam filter to On
  6. In Email > Spamd startup configuration, set Allowed IPs to include:

    This will restrict the server from receiving mail for all domains to only accepting mail from Mail Assure.

In cPanel

As the admin for the domain, or higher:

Select Email > Default Address > <domain> > Discard the email while your server processes it by SMTP time with an error message.



  1. Navigate to Service configuration > Exim Configuration Manager
  2. Set Mail setting:
    • Smarthost support to *

This should be <asterisk><space><smarthost address><double colon><port number>.

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