Error in Outlook Web App when Exchange Server 2013 users try to grant Delegate permissions to a security group: Sharing invitation couldn't be sent

Original KB number:   3188800

Symptoms

An Exchange Server 2013 user tries to grant Delegate permissions through Calendar sharing to a security group by using Outlook Web App. However, the user receives the following error message:

The sharing invitation couldn't be sent to the following recipients:Groupalias@contoso.com. Please try again later.

Cause

The behavior is by design in Exchange Server 2013.

Workaround

To work around this issue, use one of the following methods:

• Use an Outlook client to grant delegate permissions to the security group. For more information, see Allow someone else to manage your mail and calendar.
• Install Exchange Server 2016.