When opening Outlook on Windows, you might receive the error:
The action cannot be completed. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.
You might get this error if the email address that you’re attempting to set up in Outlook was already set up on the same Outlook client (like if you had the same email address in Workspace Email on Outlook, and then switched to Microsoft 365 and tried to set it up again using the same Outlook client).
To fix this issue, follow each step, in order, and check to see if Outlook is working normally. If not, continue to the next step.
Note: If you’re using Outlook 2010, you must install the Microsoft 365 patch. Please do that before attempting these troubleshooting steps.
|Restart the computer||Close all programs and completely restart your computer. Then try to open Outlook.|
|Check the Windows Credential Manager||Sometimes Outlook won’t open because the credentials are in a format that’s not compatible with Microsoft 365. Remove incompatible Windows credentials.|
|Reset the password||Sign in to Microsoft 365Microsoft 365 to confirm you’re using the correct email address and password. If you can’t sign in, reset your password.|
|Create a new Outlook profile||Make sure Outlook is closed. Then create a new profile through the Control Panel. You can set Outlook to prompt you for a profile when it starts.|
|Test the connectivity||Outlook might not be connecting to the server. Test the connectivity of Outlook.|
|Briefly disable firewall settings||Review any firewall settings that might block the connection. It might be beneficial to disable the firewall temporarily to confirm that it’s causing the error.|
|Try manually configuring Outlook||It’s always suggested to use Autodiscover first. If Autodiscover fails, try to set up Outlook manually.|