Office 365 (Outlook 2016 for Windows) - Switch from offline to online mode

Offline access lets you use Outlook on your laptop or desktop computer when you're not connected to the Internet.

If the status bar at the bottom of your Outlook window shows either of these status indicators, it means Outlook isn't connected to your mail server.

working offline status. or disconnected status

You can't send or receive email until you reconnect. Here's how.

When the status is WORKING OFFLINE

Click Send/Receive > Work Offline to turn to reconnect.

Work offline

Notice that when you're working offline, the button looks blue:

working offline

But the button has a white background when you're connected and working online:

working online

To confirm that you're connected, make sure the Work Offline button isn't blue.

 Note    If you don't see the Work Offline button Cached Exchange Mode might be turned off. For steps to turn it back on, see Turn on Cached Exchange Mode.

When the status is DISCONNECTED

If your Internet connection is working, there might be a problem with the mail server.

If you can get and send mail on the website, the mail server is fine. But your computer might need updates or there might be a problem with the account settings.

Here are some other things to try:

Send and receive groups

If the option is set at a long interval, or if you know your server's time-out interval, type a lower number in the box so Outlook will check for mail more often.