How I can change my email default?

How I can change my email default?

Hi,

I have a small different case.

I added a new email, but when I need to send a new email from contacts, for example, Zoho use my admin email (andrelvbona@gmail) and not the new email added in Zoho mail ( andre.bona@valorinvestimentos.com.br).

I need Zoho use the new email to send messages.

So, I tried to change my email ID, but zoho answer: this email exists. And is not possible to change!

What can i do?