Check to see if the new Outlook toggle is turned on or off. If it's on, please go to Troubleshooting Outlook issues. As a first step, go to the Classic Outlook troubleshooters page and select one of the troubleshooters listed. If that doesn't work, contact support for assistance.

In Outlook, sometimes your outgoing messages get stuck in your outbox and just won't send. Learn about some ways to get them moving.

Learn how to fix Outlook.com email sync issues if you can't receive or send messages.

There are multiple ways for you to send and receive email, and multiple versions of Outlook available. If the images in these topics don't match what you see on your screen, you might be using a different version of Outlook.

Having trouble connecting to your email from Outlook on your desktop? Follow these steps to let Outlook diagnose and fix errors in your Outlook mail profile that might be causing the issue.

Last updated: June 2026. For issues that are not covered on this page, we have multiple tools to help you automatically diagnose and fix a range of Outlook problems. Need more help? Talk to support.

If you are having problems with new or classic Outlook for Windows not responding, hangs, freezes, or stops working, there are a few things we can help with to get you back to using Outlook.

This issue can occur when you register a 3rd party email address (e.g., an email address that is not Outlook.com or Hotmail.com) for your Microsoft Account and don't use Outlook.com for sending and receiving email.

For issues that are not covered on this page, we have multiple tools to help you automatically diagnose and fix a range of classic Outlook problems. Check out this article: Resolve Outlook for Windows issues with automated troubleshooting tools.

Automated troubleshooting tools for Office to help you diagnose multitude of issues, such as crashes, hangs, configuration issues, etc.