How to import contacts and companies at once

I have an external list of contacts and their companies and would like to import it into Sugar. When I do it only checks on email so it only finds those duplicates. That means it then creates a new company record for every contact even if the company already exists. Because it is an external lies I don;t have company codes to check against.  At a minimum it should check name at best it should check domain. 

Thoughts? Experiences?