I get the error “is in use by a user” when I add a support address or set a user as staff

When trying to add a new support address or set a user as staff, the error is in use by a user. Remove it from the user before adding it here appears.

This error means a user with this email address already exists in the account. Run a search to confirm. An email address cannot serve as both a support address and a user identity at the same time. To use the email address as a support address, remove it from the linked user profile.

To resolve the "is in use by a user" issue:

Sign in to the Zendesk account

Click the magnifying glass icon in the upper-right corner and search for the email address

On the search results page, select Users

Select the user to open the profile.

Choose one of these actions: Change the email address for the user to another address within the user's profile. If it's a legitimate user, use a valid email address they can receive mail at. Or, Delete the user. If the user is a test user or is not a legitimate end user or agent, remove the profile. This makes the email address available again as a support address. Or, if you want to keep the user as staff, update their email address and then change the User type from End user to Staff member

After updating or removing the user, use the email address as a support address

For a high-level view on how to set up email in the account, see How do I start using email in Zendesk?