SMS Integration with ASP.Net

1. Buy a GSM Modem (preferrably a USB 3G modem from HUAWEI, ZTE, SonyEricsson, Falcom, etc.),
2. Install the modem onto your ASP.NET device and take note of the device's virtual COM Port in Windows Device Manager,
3. Download the SMS Utility from http://www.exclusivetoolkits.com/Utilities/SMSUtility.aspx
4. Follow the instructions at http://pietschsoft.com/post/2004/09/07/How-do-you-call-a-Console-application-from-ASPNET-and-get-the-results.aspx to call the SMS Utility from your ASP.NET pages

A common way is to use an email-to-sms service. Most telco providers offer that. That way, all you have to do is to generate an email to an address that corresponds to the recipients cell phone number.

OR

you have to send an email to each carrier's SMS gateway, using the phone number of the phone you are trying to contact. The trick here is knowing what the gateway is for each different carrier and then knowing which carrier the receiver is using. Take a look at this link

IMO, an easier way is to use a SMS service, but of course that has a fee attached to it.

Thanks