You may receive an error saying something similar to:
Pre-Processing Error for (username) : Error Authenticating : invalid_resource…(additional error info)… You might have sent your authentication request to the wrong tenant.
This error is common in cases where the source or target Office 365 connector contains an incorrect Tenant Name or improperly formatted Tenant Name.
In your Connectors, the Tenant Name field should not include “.com” or other top-level domain name endings; (.net, .org, etc.). This should only be the technical tenant name. You can easily find this tenant name by logging in to the tenant, opening the SharePoint app, and view the URL. It will be something like https://tenantname.sharepoint.com/…
Note, your tenant name may not be your primary SMTP domain name. You will need to verify what your actual tenant name is before proceeding.
An incorrectly configured connector looks like this:
A correctly configured connector looks like this: