Symptoms
Get below error on Spamtitan while releasing the mail as you can see in the screenshot below.
Cause
It was Spam Mail Spammer use same sender ID and tried to send spam mail.
From ID, Subject and Recipient ID is same that's why user was getting this error while releasing the mail.
Solution
Don't release the mail. It's Spam mail and this type of mail does not originate from Mithi