Improving How Outlook Classic Handles Reactions

A fix due in May 2026 will make sure that the Outlook classic client will handle Outlook reactions properly if the reactions are blocked. Of course, if tenants don’t like responding to email with an emoji, they can create a transport rule to insert the x-ms-reactions header. Detecting the header is an instruction to Outlook clients to suppress reactions that Outlook classic has been ignoring up to now.

https://office365itpros.com/2026/04/17/outlook-reactions-classic/