Are there any free services for sending SMS programmatically?

Question

I have a Rails app that needs to send SMS messages to users but does not need to receive messages.

Is there a free way to do this programmatically? If so, how free is it - do they charge if you go over a certain number of messages?

I know Gmail allows you to send SMS messages now. But I'm not sure if this means you could also send an SMS from an application through an SMTP connection to Gmail. Has anyone done this?

Answer 1

You can use udefn to send SMS for free. They provide an API.

Answer 2

If you just need to send messages, you're better off compiling as list of cellular proivders and email domains they use. Wikipedia has (what looks like) a pretty extensive list.

Answer 3

well, if you use rails, you should try this out, seems to work pretty well

Answer 4

For about 4¢ per message (it seems) you can send through this gateway:

http://www.clickatell.com/pricing/message_cost.php

There is a ruby gem that will help you interface with Clickatell:

http://clickatell.rubyforge.org

Source of info:

http://codeclimber.blogspot.com/2008/03/sms-gateway-review.html