Outlook 365 for Windows now has the Microsoft To Do service, at least that’s what Microsoft is boasting. It’s not a proper integration into Outlook and there are dangerous limitations.
To Do is a relatively new Microsoft cloud service. It’s quite different and more powerful than the Tasks part of Outlook.
With a Microsoft hosted mailbox (Microsoft 365 hosted or Outlook.com) a new To Do icon appears on the left navigation pane.
At left is To Do’s breakdown of tasks (My Day, Important, Planned, Assigned to me etc) plus any custom lists.
If you’ve used To Do elsewhere, in particular the web page version, then the Outlook window will be very familiar.
Not Really Outlook
The To Do pane in Outlook 365 has most, if not all, of the features in the web page version of To Do for a good reason.
To Do in Outlook is just a web page that MUST be online to work properly! A very sophisticated web page, likely a Progressive Web App but still something that only works online.
It’s NOT like the core Outlook features (Email, Calendar, Contacts and Tasks) which are mostly saved on your computers (a PST or OST file) and will continue to work offline.
Possible To Do data loss
In our tests, the To Do pane continues to work when offline but only if the pane is already open when connected.
To Do appears to save some information locally and let you work offline but that’s a TRAP.
In our tests, To Do changes made while offline are NOT copied to the cloud when reconnected! That means you could update your To Do, not realizing there’s a temporary Internet outage, and your changes are lost.
Must keep the To Do pane open
To Do in Outlook will stay visible when offline but only while that pane is open.
Once you close that To Do window while offline, the display is totally lost, If you try to open the To Do pane when offline, you’ll see this …
And eventually this typically vague error message.
The error message is correct, as far as it goes. It should say specifically there’s no Internet connection. However, doing that would reveal the crucial limitation of To Do in Outlook, so Microsoft keeps the message vague.