Just a FYI and for the archives...
Last night a system rebooted and tried to notify me via tmomail.net. One message got through, one didn't.
Good news is I got a bounce for one of the messages:
451 All MX servers are unavailable for domain tmomail.net
As an IT guy, to me this means that T-Mobile hasn't properly designed their email->text service. (as if posts here were not enough of a reminder). It could also be a bad implementation of greylisting.
Personally, I gave up on the service about a year ago and now send alerts to my exchange email and a Touchdown mail client rule sets off an annoying alarm (that repeats and doesn't stop)