Quite a number of the new features rely on the local Outlook data store.This means that when you are using an Exchange account, you will need to enable Cached Exchange Mode (CEM) for them to work.Note: In order to use some of the functionality in Outlook 2016, you’ll need to configure your Exchange account with Cached Exchange Mode enabled (CEM). For an overview of features requiring CEM see: Outlook 2010: New features and Cached Exchange Mode Microsoft still recommends installing the 32-bit edition of Office 2016 instead of the 64-bit edition unless you have a specific need that requires the 64-bit edition of Office 2016.However, when you have a 64-bit edition of Windows and you know that all your add-ins and other applications that rely on Office support the 64-bit edition of Office 2016, you can safely install the 64-bit edition.As this can be a huge resource hog on the Terminal Server (if not scaled correctly), contact your administrator before enabling this option. This guide contains a lot of preparation and other information to get yourself ready to ensure a smooth transition Aside from the preparation steps, this guide informs you about what to expect when you start Outlook 2016 for the first time after you upgraded and how to troubleshoot several issues you may encounter during or after the installation.
Note: In Outlook 2010, Cached Exchange Mode can also be enabled when running Outlook in a Terminal Services environment.
In Outlook 2010 and up, display of contact photos can be controlled in File, Options, People (Contacts in Outlook 2010 and newer). Administrators can use Group policy to disable contact photos.
If you disable photos, this affects the display of contact photos in the header of email messages, in the people pane, and the contact card.
When the connection to the Exchange server is not available you don’t have access to the mailbox.
Cached Exchange mode When the Outlook profile is configured in Cached Exchange mode a local cache file will be created from the mailbox.