Office 365 can be configured to work with Mac Mail on MAC OS X ver 10.5.x or greater and is setup as a standard Exchange account with some modifications.   The configuration is accomplished by using the standard auto-config in Mac Mail for an exchange account and then removing the External Server Path setting.  After this setup and modification, Mac Mail operates normally as an Exchange mail client and keeps the local inbox/folders in sync.  Optionally during the mail setup process the Mac Address Book and Calendar (iCal) application can be configured to synchronize with Office 365.

Step by Step instructions:

1. You should have received instructions from the person in your company coordinating the Office365 setup.  Using the instructions in that email; use your browser (Internet Explorer or equivalent) , login to Office365 and make sure your password is correct and that you have answered any questions regarding password setup, timezone, etc.
2. MAC OS X includes many productivity applications that work well with Office365.   These instructions are for Mac Mail.
   
3. Add Office365 to Mac Mail
1. Start Mac Mail
2. Select Preferences
   
3. Select Accounts
   
4. Add New Account – select + at bottom of window
   
4. Enter Office365 credentials
   1. Enter your Full Name (e.g. John Doe) as you wish it to appear on sent email.
   2. Enter your Office365 email address (e.g. john@configureoffice365.com)
   3. Enter your password for Office 365
      
   4. The most likely error that you may receive will be “unable to verify account” and is caused by a wrong email address or password – be sure this information is correct.
   5. Click Continue
5. Validate the configuration
   1. Review the information on this page for accuracy, if necessary use the “Go Back” button to correct any error’s and re-try
   2. Decide at this point if you wish to sync contacts and calendar’s with Office365.   Any changes to Address Book or iCal after Mail configuration is complete must be handled within Address Book or iCal.
   3. Click Create
      

      Office 365 Mac Mail OS X – Account Summary and Validation

   4. Mac mail will now take you to the main email screen where you will see any email in your Office365 account.   You have one more step in the configuration – make sure you complete step 7 below.
6. Modify the Advanced Configuration
   1. As in step 3 – select Preferences and Accounts from the Mail menu
   2. Highlight the Office365 account (e.g. john@configureoffice365.com)
   3. Click on the Advanced Tab and remove the External Server Path entry – make this entry blank
   4. Close Preferences Window (Red button – top left) and Save entry
7. Send a test email from your new account to another use and validate it works.