[Skunkworks] Setting up Google email alongside existing email server

Skunks, I have a scenario, i need to setup google apps email for students in a university, yet the already exisiting email accounts (for lecturers and HODs) should not be moved from their current email server. i.e student mails will be maintained in the cloud, while lecturers emails (already working) will be maintained at the university's server. How possible is it to have this kind of dual email handling? without ofcourse messing up the MX records of the already working emails.. -Alex