Service Restored: Apple Mail not receiving email for Office 365 Email accounts

Issue Resolved: 8/10/17 - 7: 30 pm: Microsoft has resolved the issue. 

Issue Reported: 8/1/2017 - 10:00 AM :  The helpdesk is receiving reports that Apple Mail clients running Yosemite (Mac OS X 10.10) and El Capitan (Mac OS X 10.11) are not receiving email. Apple Mail will not connect to Office 365 Exchange Online.
Issue Updated: 8/1/2017 -  12:34 PM :  OIT is in communication with Microsoft Premier Support to find a solution to this known issue.
Issue Update: 8/2/17 - 12:20 PM: OIT is still working with Microsoft on a solution. More info will be posted here as it becomes available. Please refer to the known workarounds for alternative solutions.

Know Workarounds:

• Access your email account on Outlook on the Web. Instructions on how to login can be found on the Office 365 service page.
• Convert to the Microsoft Outlook email and calendaring client.  CU Boulder has acquired licenses for the Microsoft Office productivity suite, including Microsoft Outlook, for all faculty, staff and students.  Microsoft Outlook provides the most robust experience for accessing Office 365 Exchange Online mailboxes.  More information about the downloading the software can be found on the OIT website.
• Upgrade your Yosemite (Mac OS X 10.10) and El Capitan (Mac OS X 10.11) system to Sierra (Mac OS X 10.12). Please be sure to backup your data with TimeMachine. Contact 303-735-4357 (5-HELP) for assistance.

*Note: This issue does not affect clients that are connecting Apple Mail to their CU G-Suite Gmail accounts.