Hi David,
Could you please provide us with the following information to narrow down the issue?
• How did you setup your Office 365 email account on Outlook 2011 Exchange/Pop or IMAP?
• Please verify whether the emails syncing from OWA (Outlook Web App) and Outlook 2011 without any issue?
• Have you tried to re-configure email account on your iPhone device?
Moreover, you can check and determine your Exchange ActiveSync server name, see the Finding My Server Name section below in the article:
Set Up Microsoft Exchange E-Mail on an Apple iPhone, iPad, or iPod Touch
For more information:
Mobile Phone Setup Wizard
Set up Outlook for Mac 2011
If you need additional assistance or have any questions, please do not hesitate to contact us.
Best regards,
Shyamal