My, this is harder than it needs to be. If you are using Office365, and have an address like firstname.lastname@example.org, one of the big attractions is getting access to Microsoft Exchange’s push based shared calendar system. If you naively try to share a calendar from Office365, you will merely get a readonly copy – no use to anyone.
Office365 does have exchange capability; they just don’t like to tell you what the settings are to drive it.
To set up Outlook 2013, shut the Outlook client and open Control Panel/Mail. Select E-mail accounts.
Create a new email account, choosing manual setup. Next screen, choose ‘Microsoft Exchange or compatible service’.
In the server box, type ‘outlook.office365.com’; type your Office 365 admin login as the username (e.g. email@example.com). Ensure Cached Exchange Mode is set, and click on ‘More Settings’.
Click the Connection tab, make sure that the Connect to Microsoft Exchange using HTTP check box is selected, and then click Exchange Proxy Settings.
In the Use this URL to connect to my proxy server for Exchange box, type outlook.office365.com ; check the box of Only connect to proxy servers that have this principal name in their certificate and fill the bar with msstd:outlook.com.
Check the two boxes of On fast networks, connect using HTTP first, then connect using TCP/IP and On slow networks, connect using HTTP first, then connect using TCP/IP.
On the security tab, untick Encryption and Always prompt for login credentials, and set logon network security to Anonymous Authentication.
Click ‘Check Names’ and it will prompt for username/password; give your Office 365 email address as the username, and your Office 365 password. If you’re already authenticated, it may not prompt.
Click Finish and you’re done. A new calendar, linked to Office 365 should now appear in Outlook.
On Android, go to Settings / Accounts.
Add a new account (either Email or Exchange depending on version of Android).
Enter your Office 365 admin email username. Select Manual Setup, and then Exchange.
Domain\Username (or just username) is of the form:
(do not select client certificate) – choose NEXT instead.
Password is your Office 365 password
Server is outlook.office365.com (you will need to change this from the default)
It will prompt to be allowed to change settings; let it, and on the next screen choose the services you want to sync, including calendar.