Default Email "Push" to handheld question

I really want an 8525 from Cingular unlocked. My company is moving us all to blackberrys soon and I want to know, if they choose T-mobile or Cingular as carriers, can I still use an 8525 to push the emails as I would a blackberry? I know the 8525 can do this but they told me something along the lines of incompatibility with their server. Is there any information I need to provide about the setup my company has now to get the proper answer?