In Microsoft Exchange Server 2019 or Exchange Server 2016, you set the large audience size for the organization by using the MailTipsLargeAudienceThreshold parameter. When a user addresses a message in the Outlook on the web (formerly known as Outlook Web App) to recipients that equal the large audience size, the Large Audience MailTip is shown.
Notice: This website is an unofficial Microsoft Knowledge Base (hereinafter KB) archive and is intended to provide a reliable access to deleted content from Microsoft KB. All KB articles are owned by Microsoft Corporation. Read full disclaimer for more details.