Very weird, not sure what's going on. I just bought the Pearl today for T-Mobile and on the home screen right underneath the date and time it says
"Data Connection Refused"
Odd, because on my fathers Cingular one, it says Cingular right underneath the date. I turned my wireless off then on again and it said T-Mobile...for a few seconds before it changed back.
Do you have a BlackBerry Data Plan on your account? Without a BlackBerry Data Plan you get no Email, no internet and the 'Data Connection Refused' error.
The other thing you may want to know is that today there was a nation wide outage with the T-Mobile system that affected data changes to accounts. If you do have the data plan it may take upto 72 hours to fully provision. you should go to T-Mobile.com and register and set up your email. Tomorrow reset your phone by turing the wireless off or removing the battery, then go online and send the service books to your phone. Hopefully the delay will have gone though by then.
Another thing is, if you dont plan to get the data plan and would like to get rid of the "data connection refused", you can go to Option > Network and set the Data Service to OFF.
I have a Pearl through Cingular with out a data plan. Sometimes it will say Cingular under the time, and sometimes it will say "data connection refused". I dont know why, but it likes to switch back and forth.