Using Dropbox for Mail.app over multiple machines?

I hate having 2 computers because all of my correspondence lives only on one of them. I have way too much mail to use IMAP effectively (multiple gigabytes messages over 17 years of archives), but I'd still like to be able to use Mail.app on both computers. Has anyone tried symlinking *~/Library/Preferences/com.apple.mail.plist* and *~/Library/Mail* to DropBox to use Mail.app on more than one computer? Obviously, you wouldn't want to have two instances of Mail open at the same time, but it could work.

I'm doing the same thing with Photo Mechanic prefs (to synchronize the sequence variable), and with my 1Password database, and it seems to work...