Hi,

With my experience, i would suggest you few points.

Junior/Middle Positions - You can opt for SMS, but this lacks the personal touch so prepare a nice mail draft with the JD and send it across to them through any of the mass mailing software. For middle level, this is certainly a better way.

Senior Positions -SMS is a BIG NO. Don't use SMS at all. Rather do a soft call or Cold Call and keep in mind that you are not a recruiter at that point of time but try to be a counsellor. This will help you in creating a rapport.

I hope you will find these useful.

Regards,
Rohit