There was an issue when attempting to add the app to Outlook.
Crm : IncomingEmailS2SApprovalNeeded
1. Sign in to Dynamics 365 as a user with the Global Administrator role in Office 365.
2. Click Settings and then click Email Configuration.
3. Within the Email Configuration area, click Mailboxes and then change the view from My Active Mailboxes to Active Mailboxes.
4. Select the Mailbox record that encountered the error and then click Approve Email.
5. After the email address has been approved, click the Test & Enable Mailboxes button.
6. After the mailbox has completed testing, attempt to install Dynamics 365 App for Outlook again. This can be located by clicking Settings and then clicking Dynamics 365 App for Outlook.
Article ID: 3211621 - Last Review: 8 Dec 2016 - Revision: 1