WordPress Multisite and multidomain without parking domains?

This is the scenario:
Domain1.com
Domain2.com

WordPress MU is installed on Domain1.com.
Domain mapping plugin is installed.
I’ve followed a few tutorials and I’m pretty sure it would work but the problem is that the nameservers of both Domain1 and Domain2 are pointing to the same server and from Cpanel I manage the dns. The real problem is that I host emails for both on a separate server, so I can’t park any of the domains…

Is there any solution to this???

Thanks for your help 🙂