I took interest in the article and corresponded with Catalina Rossini but the email address did not work. It came back to me as an error:

Delivery to the following recipient failed permanently:

    [email protected]

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 [email protected] No such user (state 14).

What now?