Currently, it is not possible to add a default reporter to the "Comments from emails" mail handler.

When a Mail hander is configured to use the default mail server and an unlicensed user replies to an email, the "Comments from emails" handler is invoked, the email cannot be processed because this handler cannot determine the actioner. As a result, the mail will be discarded.

Suggestion: It would be great to add a default reporter to the "Comments from emails" mail handler.

Temporary Workaround:

Use a custom mail server.