What is Exchange cached mode and should I use it?
Cached mode downloads a copy of your email to your Outlook client so that it is available to you even if you are off-line. To know if you are connected or off-line, look at the icon in the bottom right of your Outlook window. “Connected” indicates that you are communicating with the Exchange server. “Disconnected” and “Offline” mean you are not. You will know that you are in cache mode if Outlook displays “folders up to date” or “last updated” information on the bottom right, just to the left of the connection information. Cached mode is generally recommended and is particularly useful for mobile laptop users.