Pretty certain that you're wrong.

TFA shows an excerpt from the email log for his google workspace account, showing the bounce of email sent from viva.com.

Then, TFA states that he switched "the account" (his viva.com account) from using his GWorkspace address to a personal @gmail.com address, and asked viva to send another verification email. That one arrived.

At no point does TFA describe the author themselves sending a test email.