Outlook cached mode not updating
Cached Exchange Mode is the preferred configuration in Outlook 2016 and is useful in the following situations: Even when it is configured in Cached Exchange Mode, Outlook 2016 must contact the server directly to do certain operations.
These operations won't function when Outlook is not connected and can take longer to complete on high-latency connections.
Note This article is for IT Pros and admins that are deploying and configuring Outlook 2016 for Windows for users in their enterprises.
If you're a user trying to configure your Outlook settings, see Turn on Cached Exchange Mode.
By default, when Cached Exchange Mode is enabled, shared mail and nonmail folders that users access in other mailboxes are downloaded and cached in the user's local file.
Similarly, if a manager delegates access to his or her Inbox to a team member, when the team member accesses the folder, Outlook 2016 also starts caching the Inbox folder locally.
These operations include the following: Delayed delivery options are client side in cached mode and server side in online mode.
As an alternative to Public Folders, consider Site Mailboxes.
You can disable caching of all shared folders for profiles that have Cached Exchange Mode enabled.
To do this, configure the Download shared non-mail folders option in the Office Customization Tool (OCT) when you customize your Cached Exchange Mode deployment.
Outlook is configured to determine a user's connection speed by checking the network adapter speed on the user's computer (supplied by the operating system).
If the reported network adapter speed is 128 KB or lower, the connection is defined as a slow connection.