Running BES for Exchange 5.0.3 MR4 connecting to Exchange 2007 SP1. Of 26 users, there are 2 who cannot receive messages from each other on their BlackBerry. They receive them in Outlook fine sent from BlackBerry or Outlook. Checking mailbox with OWA for a reference message, see a message was delivered to Inbox. At the time this reference message was sent, there are no events logged in Application log on BES server. Any ideas on what to check?
If there's a chance it might help out, a migration to Exchange 2010 is about to be started.