We have Office 365 Pro Plus 1803. When going from 1803 Build 9126.2259 to 9126.2356, this feature is gone. I've tried this on various updated and not updated PCs. Create an appointment in Outlook. Send to recipients. Go back in to that appointment and change anything on the subject line. The earlier version gives you 3 options. Save and Send, Save and Do Not Send, and Close and don't Save. The later version has 2 options. It's missing the Save and Do Not Send. I read release notes and see this. •Fixed a hang when creating new appointments or meetings that reference Japanese eras.