How do you send sms free from computer to telephon?

1. You can use J2ME to create a software which can use your cellphone (connected to a serial or USB port of your PC) as a sending/receiving device.

2. OR you can use a GSM/SMS Modem instead (costs around 100$ roughly). Most of them come with a software CD, using which, u can send and receive SMS.

3. For only sending SMS for free, there are many other free options on the internet which you can search. email to SMS gateway may also be an option for sending SMS, eg. sending an email to @.com

Answer

A SMS text message is just an ordinary text email sent to a special server on your mobile service providers network.

Also note, no subject is required, in fact they waste additional characters to be used (remember sms text messages are limited in length).

To determine ones SMS email address, have your friend send a SMS text message to your email address. Then look at the "from" line. And there you go!