Here's the setup that's on my device right now. I use
MailStreet hosted Exchange. I also have BIS pull mail from a personal account (with
mailSnare). There are three e-mail icons on my home screen. The regular one that has always been there has a yellow postage stamp. There are two new e-mail icons with a blue postage stamp and a green arrow coming over the top from the backside of the envelope. All received messages are accessible from the yellow stamp icon. BES messages are only accessible from the yellow stamp icon. mailSnare messages are also viewable through one of the blue stamp icons (in addition to the yellow stamp icon). And any mail I have forwarded to BIS (i.e., my @vzw.blackberry.net address) is accessible through the other blue stamp icon (in addition to the yellow stamp icon).
If I click on and enter the messages from the yellow stamp icon, and clickwheel to compose, the default send from address is my BES address, although I can manually change it.
If I click on and enter the messages from the blue stamp icon assigned to my mailSnare account, and clickwheel to compose, the default send from address is my mailSnare address, although I can manually change it.
If I click on and enter the messages from the blue stamp icon assigned to my vzw.blackberry.net address, and clickwheel to compose, the default send from address is my vzw.blackberry.net address, although I can manually change it.
Does that make sense?