Problems with primary and secondary emails

Hi zoho team!

Today I changed my primary email (admin@mydomain.com) but now I can't delete my secondary email (contato@mydomain.com) was once the primary email? And something else, I can not create an email account for this new primary email (admin@mydomain.com) he is using the contato@mydomain.com email.

How do I create an email to admin@mydomain.com and how can I delete the email secundary contato@mydomain.com because in my email acconts still appears contato@mydomain.com

Thank you

Best