Lol, this might be the most disjointed thread I've read all day, nobody has even tried to answer the original question
Bit I am interested more is sending SMS to the system admin's defined mobile...what are the minimum requirements. Do we need to have account with some third party SMS sending agents?
Aaand, sadly, I don't know the answer
From what I have read, webmin comes with a built-in list of free SMS gateways for a variety of mobile providers. Pick your mobile provider from the list (in "Scheduled monitoring" settings), enter the phone number in the box beside it, and the rest is magical.
I'm not sure what you do if your mobile provider isn't in the list, that's what brought me here :P