I have a problem on my mDaemon mail server
I have 1 user that is receiving hundreds of mail delivery error as if he is trying to send emails to someone but failed...
The emails are to a weird email firstname.lastname@example.org
Looking at mDaemon logs I see that it is as if the user is really sending those emails while he is not.
Those ar the actions I took
I formatted his pc and reinstalled outlook
On mDaemon I changed the password of that user and created a complex password (10 char complex).
It worked for few hours then it is coming again...!!
My ISP is threatening to block me as he is saying thousands of emails are being sent as spams...
How to resolve this issue? What shall I do ?
BTW relay is not activated on my mDaemon server.