We would like to share information with you about cached mode in Windows and how it impacts email performance after migration to Office 365.
At the request of the customers, UITS has been migrating some accounts to the Office 365 environment before the university-wide migration on April 10th. During this process, we found that some customers with the Exchange Cached Mode setting turned off experienced a negative performance impact. If cached mode is turned off, Outlook runs slowly since all data is stored and retrieved from the cloud. We have discussed this topic at our Town Hall meetings, but since it may be a reoccurring issue for our customers, wanted to reinforce the importance having this setting on or checking the setting if a customer reports a problem. Microsoft has documentation on how to turn on/off cached mode for Outlook 2013 and Outlook 2010, and UITS has posted these links on our project website: http://office365.uconn.edu. Outlook 2011 for Mac uses caching by default and cannot be enabled or disabled.