SmarterMail - SMTP Blocks
SMTP Blocked Senders will block outgoing emails, matching the email address you specified. This is useful for temporarily blocking the ability for a user to send out emails, rather than having to disable or delete the account.
Process to adding an email address.
Step 1 - Log in to Smarter Mail as the system administrator.
Step 2 - Click settings icon button.
Step 3 - Click on Security in the left hand column (The shield icon).
Step 4 - Click on Blacklist then click on new to create a new entry.
Step 5 - Specify the email address to block, direction and a description.
Step 6 - Click Save.