A user is connected to Exchange 2007 with Outlook 2007, cache mode turned on. When they add an additional mailbox (Tools, Account Settings, Change, More Settings, Advanced, "Open these additional mailboxes"), they can view the additional mailbox just fine, but they no longer receive emails to their own account unless they click on Send/Receive. The patch for now is the schedule a send/receive every 5 minutes, but that isn't ideal. As soon as we remove the additional mailbox and restart Outlook, mail flow resumes. Any ideas? Thank you.