Sending mail when playlist runs empty

I configured that mAirlist (version 6.3.24) has to send an email when the playlist runs empty.
However, it also sends emails now and then when playlist is not running empty.

Second, last week, I programmed an one time event: Load & Play databank playlist. The result was that mairlist was sending emails until I ended the exe via taskmanager. As I received +100 emails, mAirlist was very busy sending emails instead of playing audiofiles. Is this a bug? How can this be prevented?