downloading mail

I have partioned my hard drive into two sections. One section is for Mountain Lion and the other for Snow Leopard. Unfortunately, I fooishly deleted MAIL from the Snow Leopard parition, and now I want it back. How do I go about downloading the version of MAIL that is compatible with Snow Leopard? In case you're wondering, I kept Snow Leopard because there are some valued applications that are compatible with Snow Leopard but not Mountain Lion.