Plesk 12 email series
6. How to set a return-to-sender failure message for unrouted emails in Plesk
This demo assumes you’ve already logged in to Plesk.
Now let’s learn how to set a return to sender failure, or reject message for unrouted emails.
Click "Show More" to expand the list of options for this domain.
Then click the "Mail Settings" option.
That was one way to get to this page…
Another way to get there is to click the "Mail" tab.
Then click the domain you wish to set the catchall address for.
Content retrieved from: https://support.appliedi.net/kb/a1151/how-to-set-a-return-to-sender-failure-message-for-unrouted-emails-in-plesk.aspx.