Troubleshooting a Red 'X' on Outlook Icon (Outlook in Work Offline Mode)
If Outlook has a red x on the icon in the taskbar , and emails don't seem to be coming to your inbox, your email may be in Work Offline mode. This occasionally happens automatically when Outlook loses network connection briefly.
Solution
Step 1:
Open Outlook
Step 2:
Navigate to the Send / Receive Tab at the top of the page. On the far right under Preferences is the Work Offline button.
When Work Offline is enabled, you'll have a darker gray box around the button:
.
And when it's disabled it won't have anything around it:
Once this is unchecked, any emails pending delivery to your Inbox while offline will appear.