I'm a bit confused by the whole Dial Up Networking on a treo 650 and would appreciate some clarification. Sorry if this is going over well trodden ground but I read a lot of DUN related posts and they are not quite the same as my circumstances.

I currently have a Tungsten T and a nokia phone. I connect to the internet via bluetooth and the phone from the Tungsten at GPRS speed. However if I want to get to my corporate IMAP4 mailserver I have to make a dial-in connection (PPP) and pick the mail up with PaPimail (or whatever).
This works fine and is pretty simple to setup.

There is a lot of discussion regarding the treo and the fact that some carriers disable DUN. However I'm not clear if this applies ONLY if you are dialing through the Treo from a laptop via bluetoth OR if you are dialling only from the treo ?

I live in the UK, but need to better understand how this works in the US. Do some carriers leave DUN enabled ? When disabled is this only when dialing through bluetooth from another computer or does it apply to all dialup networking connections from the Treo ?

many thanks

many thanks