how to use a personal email address for sending emails

I recently signed up with an email, but want to send out from Zoho under a different email. Unfortunately, the other email says it's in use?? I just set this email up through my website and know it wasn't used. The only thing i can figure is, maybe it was used by another Zoho user inadvertently? (typo)?

How can i get it out of the system? Is there a system admin with Zoho that i can contact for this issue?