Teleflip deosn't always work either. Tried to teleflip myself. We moved over from AT&T with our cell phones to Cingular with the BB back in mid-March and the DNS listing has yet to catch up with the change. I get an error message back that says:
We're sorry we were unable to deliver your message via Teleflip. No more delivery attempts will be made. Included is a list of recipients and the reason your message could not be delivered.
There are no DNS entries for the hostname mobile.att.net. I cannot determine where to send this message.