Some email delivery attempts are not present in the WHM -> Mail Delivery Reports interface. For example, delivery attempts rejected as outgoing spam will not display in the Mail Delivery Reports interface. Messages rejected as outgoing spam will be logged in
/var/log/exim_mainlog as follows:
2021-05-31 15:43:17 1lnAxx-OoANdn-XX H=mail.server.hostname [203.0.113.0]:12345 X=TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256 CV=no F=<firstname.lastname@example.org> rejected after DATA: "The mail server detected your message as spam and has prevented delivery (50)."
Mail delivery attempts that have been rejected after DATA are not stored in cPanel's eximstats database at the time of this writing. They are therefore not available in WHM's Mail Delivery Reports interface, which uses the eximstats database.
We have an existing improvement case for our developers to add these rejected deliveries to the eximstats database. The internal case ID is CPANEL-27257 for your reference.
These rejected deliveries are logged in
/var/log/exim_mainlog. We recommend using the
exigrep utility to search the log manually for these messages. For example:
exigrep $email-address /var/log/exim_mainlog