b4 i was using txtmail for the last few years. last few weeks i cannot use it? any special reason. i have a sidekick II. when i create a message n send it. it says message sent. yet the recipient did not receive it.save a lot by using txt mail. because i can send sms abroad and billed it as domestic
:welcome: to WirelessAdvisor! The T-Mobile e-mail domain for Sidekick users (after the @ sign) is not the same used by T-Mobile phones. Thus, I do not believe the Sidekick uses the same 500 server as the phones do. You should call T-Mobile Customer Care and explain the problem, they should research it for you and provide the correct instructions for sending e-mail from a Sidekick.
This is the support page for the Sidekick II instructions on sending e-mail. It does not mention sending to 500, in fact, the procedure is completely different on the Sidekick.