Problem Reported:

The mail sent within the same domain got quarantined/blocked on the SpamTitan.


Observations:

Check the mail in Spamtitan > Report > History

Check the score, check due to which Rule score has been increased. You can check that in 'View Source' option.

If the rule is, tests=[ANTISPOOF_DOMAIN=25 the mail is blocked in spoofing as the Sender and Recipient domain are same.


Solution:

Add the sender domain in SpamTitan domain allow list

https://helpcenter.mithi.com/en/support/solutions/articles/48001229291--securemailflow-spamtitan-whitelist-domain