*Current Status:* Engineers completed the development phase of the fix. Subsequently, engineers tested the fix and confirmed that it restores service. Engineers are now deploying the fix to the affected environment.
*User Impact:* Affected users are unable to receive email messages when accessing Exchange Online through Internet Message Access Protocol (IMAP). As a workaround, users may be able to access email via Outlook on the web. [Catmail: https://catmail.ohio.edu ]
*Customer Impact:* Analysis of incident scope indicates that a limited number of customers appear to be impacted by this event. However, those customers affected likely have a large number of users experiencing impact. Engineers have received a few isolated customer reports of this issue.
*Incident Start Time:* Monday, January 18, 2016, at 12:00 AM UTC
*Estimated Restoration Time:* By Saturday, January 23, 2016, at 2:00 AM UTC
*Preliminary Root Cause:* As part of our efforts to improve service performance, an update was deployed to a subset of code which is responsible for obtaining the subscribed folder list. However, the update caused a code issue that prevented the list from being automatically loaded.
*Next Update by:* Saturday, January 23, 2016, at 2:00 AM UTC