To set up a way of sending emails from an address without getting lots of replies.
Set up an id as usual in the admin client: with single word ids or mail addresses I use the last name.
Tick to set up the mail box for now. You can always delete it later.
Go to Server's Name and address book NAB.
Go to Server/Configurations/Configurations view aka Servers\Configurations and edit the relevant server's document.
Click on the Router/SMTP Tab.
Click on the Restrictions And Controls Tab.
Click on the SMTP Inbound Controls tab
Add the email address to "Deny messages intended for the following internet addresses:"
These addresses are semicolon separated.
Save and close.
Open up the mail db and send a few emails, then try replying to them. It should fail.
Save any agents with the id.
Delete the mailbox if you need to. Might be worth keeping for tests though and for manual emails.