You want to suppress the requests notification when sending the emails, you configured in transaction SCOT for the SMTP Settings as follows but it does not work:

When you send E-mails to the recipient, in Outlook the recipient will receive the additional mail named
“Successful Mail Delivery Report” with the original mail like the following:

If you do not want to receive the requests notification like this, you can do the following settings in transaction SCOT -> Outbound Messages -> Settings -> Tab Status Requests -> enter “*” and “Only if Errors” in Address Area：

After perform this setting the requests notification will not be sent then.