Formula Field "Email" Output or Allow Email Notifications to go To value from formula field

Formula Field "Email" Output or Allow Email Notifications to go To value from formula field

We have a formula field that will always output an email address from one of two other existing email address fields:

However, when try to put use the output of this formula field in Email Notifications, it is not showing up:

There needs either be a Formula Return Type of "email" or Zoho really needs to allow non-email fields to be used in the "To" field of email notifications.