One major difference in High Sierra 10.13 is the switch to Apple File System APFS which does NOT support disk compression. One way to reduce the disk space used by Outlook for Mac was the disk compression see It’s method of saving data on the disk is wasteful and quite different to the PST/OST system in Outlook for Windows. Unless there’s a specific reason for keeping an older MacOS running, Office 365 for Mac customers should do proper backups then upgrade to at least Sierra 10.12 if not the latest MacOS Mojave. Cautious ones might wait a few months before updating (just like Windows users). Most Mac users update their MacOS relatively soon after an update comes out. The existing ‘Office 2016 for Mac’ code base is kept, for compatibility with older MacOS. Office 365 with El Capitan 1.11 or earlier. The difference is that Office 365 users get new and updated features while Office 2019 is fixed and doesn’t get updated features. That means both Office 365 for Mac and Office 2019 for Mac users share common code. These customers moved to the same code base as Office 2019 for Mac. The code base for the product changed depending on the version of MacOS being used. What happened back in September 2018?īack in September 2018 there was a mostly hidden switch in Office 365 for Mac software. But no updates, because those updates need the more recent Mac OS. If your computer has 10.11 (El Capitan) or earlier, Office 365 for Mac will still work and get Microsoft’s mainstream support.

The ‘subscription’ Office 365 for Mac available now needs the MacOS released in the last two years. Office 365 for Mac needs Mojave, Sierra or High Sierra In short: Office 365 for Mac gives you the latest features and updates if you have the latest MacOS (Mojave 10.14) or the two before (10.13 High Sierra or 10.12 Sierra). The situation appears confusing, so we’ll try to break it down for you. Microsoft has a blog post might be accurate, but it doesn’t exactly shine with clarity. Some Office 365 for Mac users might not be getting the latest and greatest features. Office 365 for Mac users might well be confused about compatibility with their MacOS.

Microsoft outlook for high sierra