What does it mean when Cortana says "This is a long one" during email readout?

Applies To
Outlook for Android Outlook for iOS

Important

Outlook Mobile will be retiring the Play My Emails feature in June 2024. To learn more, see End of support for Cortana.

Cortana will preface email messages that take 30 seconds to one minute to read with, "It's a long one." If it will take more than one minute, Cortana will say, "It's a really long one."