Campaigns Error Message: "This email address has been already used in some other organization. So you cannot add/invite this user."

Campaigns Error Message: "This email address has been already used in some other organization. So you cannot add/invite this user."

I am trying to add a new user to our Zoho Campaigns account, but when I attempt to do so, I receive the error message, " This email address has been already used in some other organization. So you cannot add/invite this user. "

This user is associated with another Zoho Campaigns account that she created on her own. I saw in another post that you need to delete her Campaigns account in order to free her up so I can add her to our account.

Please delete her account when you can. Her email address is donna.chabrier@taxaudit.com. Her account number is 646781781

Thanks,

Matt