: These older versions were built for PowerPC processors and relied on the "Rosetta" emulator. Because Apple removed Rosetta starting with OS X Lion, these versions will not run on 10.7.5 Microsoft Learn 2. System Requirements for Office 2011
: Also compatible with Lion, though it lacks some of the features and interface refinements found in the 2011 version. Apple Support Community System Requirements for Office 2011 Microsoft Office For Mac Os X Lion 10.7.5
If you use Outlook 2011, note that it uses a database file ( .olm ). For Lion, ensure you do not let the database exceed 15 GB, as performance will plummet. Also, you cannot connect to modern Office 365 Exchange servers without enabling “Basic Authentication” (which Microsoft is phasing out globally). : These older versions were built for PowerPC