- Open Account → Properties for the account you want to send protected attachments from.
- Go to the Transport tab.
- Under SMTP server, enter the gateway's inbound server settings — server address and port.
- Enable Use SSL/TLS (port 465) or Use STARTTLS (port 587), matching the port you entered.
- Under Authentication, use your account email as the username and enable password authentication.
- Click OK, then send a test message to confirm delivery.
The Bat! keeps separate transport settings per account, so this only affects the
account you edited — other accounts in the same profile keep sending through their
own existing servers unless you repeat these steps for them too.