Using Classic Outlook on Windows for personal email, calendar, and contact management
Hey David,
The long-term plan is to have consistent end user reporting in outlook across all clients (including support for shared and delegate mailboxes) using in-build report button. It is today available across Outlook for web, new outlook for windows, classic outlook for windows, outlook for mac. Android and iOS should ship soon - Microsoft 365 Roadmap | Microsoft 365
Once this report button is available consistently across all outlook clients with shared and delegate support, we will take the long path (years) to deprecate the report message and report phish add-in.
At the moment all three - report message, report phish and the inbuild button are available and they are like doors to the same house. So, whatever the end user uses the experience for the admin will be same as they call the same API internally which follow your user reported settings.
please let me know if you need more clarity or have any more questions.