Hi,
I don't have any experience of Blackberrys, but use a Windows Mobile 6 Device from vodafone, I think it's called the v1615, and this pushes email to me.
They're great - I need to check emails on the move and this works fine. I also use it to synchronise with my Outlook Calendar, Tasks and Contacts, it does this on the move because I use a
www.1and1.co.uk Exchange account (I'm not an employee by the way).
Hope this helps, let me know if I can be of any more help.
Marky