Overview:
After you update your Windows password and before you can use Mimecast, you have to authenticate your Windows password in Mimecast.
Instructions:
- You may see this error in the lower right hand corner of your screen:

- To fix this you can either click on the error message or go to the Mimecast tab in Outlook and click on the gear icon that says account settings:

- In the next window, click Fix in the Domain Authentication section.

- Enter your Windows password and then click Submit Password.

- You should see a green check mark and the word Active. Now you are authenticated. We do not use Cloud Authentication, and it will always say missing password - that won’t affect anything.

- Under the Mimecast tab in Outlook you should now have the full display of options:
