what should (and shouldn't) be in Mail folder?

[malch]

Hi there,
I'm 'migrating' from an old Snow Leopard boot drive to a new Mountain Lion boot drive, and don't want to move everything, so I'm doing fresh installs of my key apps.
But before I copy my old Mail folder (~/Library) to my new ML boot drive, I'd like to know if I've got extra flotsam and jetsam in there that I don't need.
Would someone kindly tell me what folders and files should be in the Mail folder? (right now I've got 7 folders and 8 files, including 'AvailableFeeds' and 'BackupTOC.plist).
thanks for any help,
malch