Office 365 (Outlook 2016 for Mac) - Switching between offline/online modes
Offline access lets you use Outlook on your laptop or desktop computer when you're not connected to the Internet. Note: You cannot send or receive messages when you are in Offline mode.
When you switch between working online and offline, all email accounts within your Outlook profile are changed.
- Select Outlook in the upper right.
- Select the Work Offline option.
- There will be a check mark next to Work Offline when you are in Offline Mode.
- Repeat the steps to return to Online Mode.