Office for Mac is receiving a new Fast Ring update for those in the Office Insider Program.
Latest version 16.43 (20100803) introduces support for S/MIME (digital encryption) and Mandatory Label for tenant administrators.
Outlook
New features
- S/MIME: Apply digital encryption to control who can view messages and use signatures to ensure emails haven’t been tampered with.

- Mandatory Label: As a tenant administrator, you can now require that a label be applied before users can send emails.

Bug fixes
- Calendar: When creating an event, the event-end time-picker is now easier to use
- Calendar: Fixed a bug in new time proposals where attendee information was getting lost
- Contacts: Fixed a bug where the contact details window does not open when Outlook is offline
Known issues
None