Send notification delivery status to Manager: HTM attachment?

Hello. I am trying to better understand if I can change the behavior of the service when it sends the notification to the manager, as per the configuration:

The e-mail reaches the recipient (the manager) in this way:

The body is empty and the text that should go in the body of the e-mail is in the file ATT00001.htm.

Instead, the list of users can be found in the "Soon-To-Expire ..." file, but this is correct because it is set up that way on the tool.

The question is, can I prevent the body of the e-mail from remaining blank? It is shown this way by both Outlook client and WebMail. I would like to understand if this is a problem generated by ADSelfService Plus.

Thanks.