AADSTS50173: The provided grant has expired due to it being revoked, a fresh auth token is needed. The user might have changed or reset their password. The grant was issued on 'YYYY-MM-DDT00:00:00.0000000Z' and the TokensValidFrom date (before which tokens are not valid) for this user is 'YYYY-MM-DDT00:00:00.0000000Z'.
The solution is to proceed with re-authenticating the account.
This may have happened because the email administrator revoked all authentication tokens. This error indicates that the authentication token used by Nylas was valid, but the email server will no longer accept it because it won't accept any authentication tokens older than the specified timestamp in the error message. Please reach out to the user's email administrator if there are further questions about how this happened.