We're often asked, "How do I add an Office 365 Shared Mailbox to my iPhone's Outlook App"?
So below I've put together a guide to show you.
1. Go to Settings (Cog icon) from within your iPhone's Outlook App.
2. Choose Add Account, Add Email Account and enter the email address of your shared mailbox.
3. On the latest Outlook App, you'll be presented with the Authenticator box, but choose Note Office 365 from the top right-hand corner and Change Account Provider.
4. Choose IMAP and Use Advanced Settings. Please see screenshot below for the way to complete each box in order to connect your Shared Mailbox.
To confirm the screenshot...
Email Address: firstname.lastname@example.org Display Name: Anything you want, but I recommend the name of the Shared Mailbox Description: Same as above IMAP Incoming Email Server: smtp.office365.com:993 IMAP Username: email@example.com\firstname.lastname@example.org Password: your mailbox password SMTP Outgoing Email Server: smtp.office365.com:587 SMTP Username: your mailbox, e.g. email@example.com SMTP Password: your mailbox password