Outlook messages in inbox not displaying

My inbox shows either nothing or a fraction of what is really there. Webmail shows hundreds of messages, Outlook desktop shows a strange sparse selection.

New messages notify and then vanish from the list. Where is my inbox hiding?

Messages that exist on the server but hide in the desktop list are nearly always a view problem or a sync window problem, in that order of likelihood. Both are settings, not damage.

1

Check for an active filter first: look at the top of the message list and the status bar for the word Filter Applied. On the View tab open View Settings, click Filter and hit Clear All if anything is defined. A stray filter, often an accidental click on Unread on the ribbon, produces exactly the sparse inbox you describe.

2

Reset the view entirely if the filter dialog looked clean: View tab, Reset View, confirm. For stubborn cases close Outlook and restart it once with Win+R, outlook.exe /cleanviews, which rebuilds every folder view from defaults.

3

Check the sync window next: File, Account Settings, double click the account and look at the Mail to keep offline slider. Set to a short window, it hides everything older than that from the list, with only a small link at the bottom of the folder, click View more on server, that people scroll past. Drag it longer if you want more history visible locally.

4

If the list is still wrong after all three, rebuild the local cache: close Outlook, rename the OST in %localappdata%\Microsoft\Outlook and let Outlook re-download fresh from the server that webmail already proves is intact.

The vanishing new messages detail in your case smells specifically like the Unread filter: a new message notifies, appears, you read it and it drops from the filtered list instantly. Check that ribbon toggle before anything else, one click may end the whole mystery.

It was the Unread toggle, must have clicked it reaching for something else. One click and four hundred messages reappeared. Slightly embarrassed, entirely grateful.