Outlook is installed on more devices than Microsoft's Authenticator app. Why integrate authenticator functionality into another app? The answer lies in usage statistics. The decision to use the Outlook app, and not Microsoft's main Authenticator app, may look strange on first glance. Microsoft reveals that it allows organizations to enable multi-factor authentication for work or school accounts by using the Outlook app. Microsoft Authenticator Lite is limited to commercial partners. While any form of multi-factor authentication improves security over accounts that use none, using apps is more secure than using SMS, as codes as transmitted in clear text if the latter option is used. Microsoft notes that accounts are '71% less likely to be compromised' than accounts that use SMS codes for two-factor authentication.

Once enabled, Outlook mobile users may use the app as a two-factor authentication tool to verify sign-ins. Today, Microsoft announced the general availability of the Authenticator functionality in the Outlook applications for Android and iOS.

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