The first thing many of us do and is something that we shouldn't, and that is to ask Shaykh Goolge (D.C)
Plenty of do's and don't out there.
Asslamo Allaikum Respected Mufti Ismail Moosa Saheb (HA),
In UK many Muslims send SMS (text) messages which contain some advice or some Hadeeth or simply "Jummuah Mubarak" on fridays to others Muslims.
P.S: Awaiting response.
This cannot be undone and I am sure it will be greatly appreciated.