Even when you install Office 365 ProPlus, the default Email Application and the mailto link association doesn’t get changed to Outlook.
I wanted to change the default application for this to Outlook and also whilst I was at it, change the default PDF reader to Adobe Acrobat Reader instead of Microsoft Edge. To do this in Intune we first need to create the default file association XML file. This XML file should only contain the associations you want to change. If its not listed in the XML it will not be changed. The XML file I created to change these is shown below:
Unfortunately, Intune can’t accept the XML file directly. We have to convert it to base64. You can do this easily at the site https://www.base64encode.org/. Paste in the XML at the top, click encode and it will give you the output.
The Base64 encoding is:
Once we have our Base 64 encoding, pop into Intune, create a new configuration policy with the following settings:
Name: What you want to call the policy
Description: A description you would like to give
Data type: String
Value: Your base 64 value obtained above.
Apply it to your users. When the user next logs in they will get the new associations take effect.