Outlook inbox not previewing new emails

HR303 First off, let's double check your account settings. Go to Account Settings under the File tab and confirm that the server types are entered properly for each connected inbox, and that the option to download new content is selected. Next, if you have any IMAP accounts, enable the cached exchange mode setting under File > Options > Advanced. This should sync the folders automatically. Also, I want to verify that the rules and alerts are monitoring the right folders. Under Manage Rules & Alerts, check if your inboxes are being tracked for new mail.

Additionally, make sure your folders are flagged as favorites so they display notifications. Right click each inbox, choose Properties, and check "Show in Favorite Folders" on the General tab. Finally, go ahead and restart Outlook to refresh all the connections and folders.