I have two email accounts in my Outlook 2013. I ran out of space on one and moved, in Outlook, a large folder 'Personal' which has a lot of subfolder structure. This worked well within Outlook but I cannot see the 'Personal' folder in either the webmail Gmail interface or on my iPhone mail client. I have changed the Outlook root folder to [Gmail] but this seems designed to solve a problem the otherway around (Gmail folders not showing in Outlook rather than Outlook folders not showing in Gmail).
Thanks - Mick