Conversations about calendar items don't go to members' mailboxes
Scenario: A calender item is created directly onto the group calendar via Outlook 2016 and the group is invited. The item correctly shows up on the group members' individual Outlook calendars. HOWEVER, if a member responds to the calendar item (for example, to propose a new time), the e-mail goes only to the group mailbox and does not get forwarded to any of the members, even if the members are all subscribed to the group mailbox. Therefore, none of the members are aware that anyone has proposed a new time and the communication is essentially lost. For more details, Microsoft staff can refer to Office 365 ticket #5426250.