Email from PC to Mobile - possibility and procedure required.?

Can we send Email from PC to Mobile. If so, how the ID has to be written to send the mail from PC to Mobile of AIRTEL, HUTCH, BSNL, SPICE etc. In the case of Airtel Mobile with Karnatake SIM the procedure is Mobile No. followed by "@airtelkk.com". The right answer in this regard will enable a number of users to effectively utilise the facility.