Compose button missing in Outlook

Hi, let me help you.

What happens when you tap Ctrl+N on your keyboard?

Have you tried restarting your computer?

For classic Outlook, first try a quick ribbon reset: right-click anywhere on the ribbon, choose "Customize the Ribbon," and click "Reset all customizations" at the bottom — that fixes it most of the time if the New Email button got hidden through a ribbon tweak.

If that doesn't do it, the next likely cause is an add-in. Launch it with outlook.exe /safe (Win+R, type that, hit Enter) and see if Compose shows up in safe mode. If it does, disable your add-ins one by one under File > Options > Add-ins to find the culprit.