An update for Outlook on iPhone adds voice commands powered by Microsoft’s Cortana assistant.
Now Outlook users with an iPhone or iPad can rely on Cortana’s voice capabilities to schedule meetings, search for emails, and read out a reply to an email. Outlook users can hold down the Google-like plus sign icon on iOS (and soon Android), and then tap the microphone icon to “Use Voice” to tell Cortana what to do in Outlook.
App Store: Outlook
Check It Out: Outlook for iPhone Adds Voice Features With Cortana