yesterday I did an exercise from the learning material, and when I closed the message window got a message from FileMaker asking if I wish to cancel the script on continue.
Is it possible you had inserted prior to the Send Email step a script setp to handle errors ?
Nope, FileMaker sends the data to your email application blindly. The failure is in another application window so it can not be tracked (at least natively, plugins, it might be possible), to track it.
If it was controlled by FileMaker, error code 1 would be the expected return (user cancelled action).
FileMaker would only be able to track the failure if the send mail script step itself failed (e.g. no email application installed).
Some error codes you might encounter are error 3 (command unavailable), or 1501-1507 (SMTP errors)
That's only applicable if you use the native SMTP client settings in the send mail script step, not if you send it to the windows default mail application.
i donot see , any prompt to cancel or continue the script.