Hi Gunjan Singh,
First of all you have to post this question under ABAP blog. Below is the link.
Answer to your query is:
In SOST there will be a basis settings, like the mail has to be triggered for a stipulated time, means for every 1/2/3...10 minutes like that. May be when you are in SOST and clicking... the time stipulated time reaches and triggering the mail.
As per my knowledge there is no setting like, if we click on SOST mail, then only it will trigger the mail.
Hope I have cleared your query.