Windows - The default Mail application can be changed by typing "default email" into the Windows device's search bar. This bar is typically in the lower-left corner of the Windows device and states "Type here to search." One of the recommended choices that should appear is "Choose a default email app", select this option and then select the app under the "Email" text to then be prompted to change your default mail application. The application will then default to this updated mail application the next time a Share+ email is created.
iOS - The default Mail application on iOS is the Apple Mail app which means that the Share+ link cannot be automatically shared through a separate application, such as the Outlook app. Instead, our recommendation is to update the Apple Mail application's settings to include your Microsoft Outlook account. This can be accomplished by first opening the "Settings" app on your iOS device and then selecting the "Passwords and Accounts" option. Under "Accounts" there should be an option to "Add Account" which should be tapped. Select the applicable mail app option on this page and then follow the prompts to add the Outlook account to the Apple Mail application.
Android - The instructions for how to change the default mail application on an Android device can vary depending on the Android OS being run, but generally the option can be located in the Settings of your Android device, in the Apps section of the settings, and then in the cog icon located in the upper-right corner of the Apps page. There should be an option to change your default email application within this page.