Access vs. Gmail/Google for Education

I teach at a small, private school that is looking to streamline our communication, specifically via e-mail.  It is key that our e-mail and information sharing is secure, as we work with a high-risk population and need to share confidential information on a daily basis.
Any suggestions about using Access vs. Gmail/Google for Education?!?

Thanks in advance for your suggestions and ideas! : )

Best,
Meagan