How to Disable the outlook reaction in Exchange online

Hi All

Hope everyone is doing fine, today we are going to see how to disable the reactions  in exchange online outlook / OWA through exchange Transport Rules

Microsoft is giving organizations a way to disable Outlook reactions. The server-side block is rolling out now and should be complete worldwide by the end of September.

Outlook reactions allow users to respond to messages with a graphic reaction using outlook or OWA

The idea is that recipients can respond to message by selecting a reaction rather than typing out a reply. 

Many organisation doesn't want to use this feature to their end users as like social media platforms , like whatsapp, Facebook etc..

To Disable the feature

To disable outlook reactions, we should use the parameter x-ms-reactions: disallow in message header for an email using the Exchange Transport Rules , 

Via Powershell

# Connect to Exchange Online

Connect-ExchangeOnline 

# Define the custom header and its value

$CustomHeaderName = "x-ms-reactions"

$CustomHeaderValue = "disallow"

$RulePriority = 1

# Create the mail flow rule

New-TransportRule -Name "Disable outlook  Reactions" -SetHeaderName $CustomHeaderName -SetHeaderValue $CustomHeaderValue -Priority $RulePriority

Outcome

After the transport rule takes effective,  we can see the disabled Smile Icon as below

Summary

Microsoft may be develop in feature to  ability to disable the feature in tenant level settings in M365 (GUI ) It may take some time, , but at least it’s now possible