Symptoms
In Microsoft Exchange Server 2019 or Exchange Server 2016, you set the large audience size for the organization by using the MailTipsLargeAudienceThresholdparameter. 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.
Resolution
To fix this issue, install one of the following updates:
For Exchange Server 2019, install the Cumulative Update 4 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.
For Exchange Server 2016, install the Cumulative Update 15 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.
References
Learn about the terminology that Microsoft uses to describe software updates.
