Adding A Shared Office 365 mailbox to iPhone

In this example, Bob wants to have access to Contoso’s sales email box:

1)    Settings > Mail, Contacts, Calendars > Add Account
2)    Choose Other
3)    Choose Add Mail Account
4)    Name: Contoso Sales
5)    Email: sales@contoso.com
6)    Password: (Bob’s O365 password)
7)    Next
8)    Make sure IMAP is selected
9)    Incoming Mail Server
          a.    Host Name: outlook.office365.com
          b.    Username: bob@contoso.com/sales
          c.    Password: (Bob’s O365 password)
10)    Outgoing Mail Server
          a.    Host Name: smtp.office365.com
11)    Click Next

 

This is verified on iOS 9 and O365 as of 12/2/2015