Can I run 2 companies within 1 Zoho instance?

Can I run 2 companies within 1 Zoho instance?

Hello, I manage 2 companies. 
Each company has its own, separate email domain.
I can only have 1 primary email address.
How can I set up Zoho so that it captures emails from the 2nd email address within the CRM?
Right now, I can only choose to have 1 email account synch with records in the CRM.

keywords:
multiple companies
multiple email addresses