Here is presented an example router an transport for redirecting mail addressed to e.g. user@07123456789.sms to the Kannel SMS gateway.

We have a workflow system that generates event driven emails, so it was a natural choice to use Exim for SMS integration, especially after having already configured Hylafax.

Our Configuration

* Slackware 12
* Exim 4.68
* Kannel SMS gateway
* Ericsson F251m

The Ericsson F251m is a FCT (Fixed Cellular GSM Terminal), sometimes known as a "Premicell", that additionally has a RS-232 serial port allowing it to be controlled by Kannel http://www.kannel.org/.

I will not discuss configuring Kannel here, other that to remind you that both the bearerbox and smsbox daemons should already be configured, tested and running as described here http://www.kannel.org/download/1.4.1/userguide-1.4.1/userguide.html#AEN4201.

Your Exim routers section will require something like this:

sms:
        driver = manualroute
        transport = sms
        route_list ="*.sms"

Transports will require:

sms:
        driver = pipe
        group = exim
        user = exim
        command = "/usr/bin/lynx -dump \"http://localhost:13013/cgi-bin/sendsms?username=userxxx&password=passzzz&to=${extract{1}{.}{$domain}}&text=${tr{$header_subject:}{ }{+}}\""

this is a simple replace of spaces with "+" though given a little more time there should be a full URL encoding of the message text (which comes from the subject line only). A URLEncode expansion operator would be useful.

Only the subject line is relayed as a SMS. This was for convenience and compatiblity of being able to already send SMS to some Orange mobile users through the Orange email to text facility, which similarly displays the subject line as the SMS text message.