- Now compatible with Mail in Mac OS X 10.6.4
- Updated copyright year

• Fixed crash on notification when Safari 4 beta is installed ([65a0bcf23292], fixing #336354) We don't know for sure whether this also happened with Safari 4.0 release, but whether it did or not, it's fixed now.
• Fixed another crash, first seen in betas, on PowerPC machines ([0d7cf6a69fde], fixing #385444)
• Only show notifications for unread messages ([b19d240b576a])
• Took out a little more insurance against the possibility of clobbering an Apple method when running under a future version of Mail ([caae0ed9a580])
• Internal refactoring, eliminating an assumption about Mail's internal nature ([f8a902d33769] and [c36ddc8e6b22])
• Now loads its preference pane into Mail's Preferences window by method swizzling, which is explicitly supported in 64-bit Mac OS X, unlike the previous technique of class posing, which is explicitly not ([3be8b67aac72], fixing #363176)

Version number was changed, 2.1 is actually 1.1