I am wondering if anyone has been able to configure an LEM rule to alert them via SMS? I recall pre 5.7 that you could call a script, but cannot see that option any more in 5.7.0. I suspect it is achievable by sending an email to an SMS Service which converts email to SMS, or use the correct email address for the mobile provider e.g. email@example.com where some mobile providers can send an email to a phone as SMS/MMS.
I've made it work as described, using the carrier's e-mail-to-sms services. You can have a rule fire multiple "Send E-mail" actions, so I built a template that was short and sweet (and hopefully less than 140 characters) that would be used for cell phones while simultaneously sending the more verbose e-mail to inboxes.
Looks like someone more diligent than me got all the e-mail sms gateways together: