I have migrated 4 computers from POP email to Outlook 365. When setting up each users Outlook 2007 mailbox with the Outlook 365 account, the Cached exchange mode box was checked off. I then imported all 4 users PST files to restore historical emails, calendar info, etc.. After letting everything migrate overnight, I found all 4 mailboxes with a "Waiting to update this folder" message next to "Connected to Microsoft Exchange" in the bottom bar of Outlook. I sent test emails to all 4 accounts but they took hours to be received. After googling the problem, someone advised to uncheck Cached Exchange Mode. This fixed the "waiting to update this folder" message and new emails are coming in immediately. The problem is after I unchecked Cached Exchange Mode, at least half of the historical emails are missing. When I go back and recheck Cached Exchange Mode, the emails are there again. What do I do to show all messages without having Cached Exchange Mode on?