Forwarding from Office365 Hosted Exchange to Inbox

1. Inside your Office365 account you will want to create a mailbox for each email address you'd like to share with Inbox.
2. Create a Mail Contact as well. The mail contact should have an external email address that is your shared address (ie: [e-mail])
3. On the top right, where you see the name of the currently logged in user, select "Another User" from the drop down.
4. Select the shared mailbox user that you created in step 1
5. This should open a new window where you are now managing the shared user. Select "Organize Email" from the left side of the screen.
6. Create a new inbox rule for that user that does the following: apply to all new mail, redirect messages to -> Mail Contact from step 2
7. Save the rule.

That should be all there is needed. The flow of events is as follows:

Customer emails [e-mail] -> email goes to Office365 and is hit by the inbox rule -> message is redirected to the office365 mail contact -> message goes to Zendesk Inbox