Yes, you can add a new contact with the same email address as far as it satisfies the following rules:
All External Contacts for the same company must have a unique email address.
The specified email address must not already be used for a team member.
No more than one External Contact with the same email address can have roles assigned to it.
If you need further help, feel free to contact our support team via chat or by emailing support@avaza.com.