Originally Posted by Hulk
From mailserver (the BES polls it and grabs the email) -> BES -> SRP -> Carrier -> Handheld..
Just for clarification...
BES only polls for mail in a Domino or Groupwise environment. It does not poll for mail in an Exchange environment. Exchange uses a UDP notify packet sent from the Exchange server to BES to alert BES that there's new mail in the user's mailbox.