Note that this will disable the backspace key everywhere in Outlook, however, it will work when you are actively typing.
To enable backspace any Outlook item, simply type a character or space at the end of the text you want to delete to turn Backspace on temporarily.
The first time you use Archive, you'll be asked to let Outlook create an archive folder called Archive, or you can select an existing folder.
If you use Exchange Online or and previously used Archive in Outlook on the web or Outlook on a device, Outlook will use the folder you previously chose.
Dynamics 365 for Outlook is for Microsoft Dynamics 365 users who need access to Dynamics 365 data while they are using the familiar Outlook application.
Before you and your users install Dynamics 365 for Outlook, be sure to have completed your desired customizations.
In particular, for best performance, you should ensure that you enable only the minimum required entities and views for offline use in Dynamics 365 for Outlook.
After Office 2016 16.0.6741.2014 (or higher) is installed, users will see an Archive button on the home ribbon, next to Delete.
Not to be confused with the old Archive function, which is now called Clean Up Old Items, or Auto Archive, this Archive button is an extension of the Archive button in and Outlook on the web, moving selected messages into a single folder.
For more information about customization, see the Customize your Dynamics 365 system.