For security reason, Microsoft has deprecated the use of SHA-1.For more information, see Microsoft Teams installations on a Mac. Starting with Version 16.21, Microsoft Teams will be installed by default for new installations if you're using the Office suite install package.The following information is primarily intended for IT professionals that are deploying Office for Mac to the users in their organizations. Office for Mac that comes with an Office 365 subscription is updated on a regular basis to provide new features, security updates, and non-security updates. Learn more Starting with the 16.17 release in September 2018, this information also applies to Office 2019 for Mac, which is a version of Office for Mac that’s available as a one-time purchase from a retail store or through a volume licensing agreement. For security reason, Microsoft has deprecated the use of SHA-1. Office 365 Commercial customers can get the new Outlook for Mac by accessing their Office 365 Portal, (Gear icon > Office 365 Settings > Software > Outlook for Mac icon) or visiting the Software page Office 365 consumer subscribers can get the new Outlook for Mac by going to their My Account page. Try Microsoft Edge A fast and secure browser that's designed for Windows 10 No thanks Get started Microsoft. Learn how to install Office 365, Office 2016, or Office 2013 on your PC or Mac. Free Download For Microsoft Office For Mac.