If you've used Microsoft Outlook for a while, you know that it can slow down... In fact, when not looked after, Outlook can become nearly useless.
Users have complained for months that Public Folder Favorites were not being cached in Outlook 2016, even though caching Public Folder Favorites was enabled in Account Settings, More Settings.This also affected the ability to search public folders: because the items weren't cached, Outlook wasn't indexing the folder contents.Simple solution – turn off “Download shared folders.” If you do this, all Shared Folders will no longer be stored in your offline cache.As a result, you’ll be reading these folders directly from the Exchange Server, so you will experience delays as the mail is being accessed and downloaded. The “Mail to keep offline” slider in Office 2016 also affects shared folders. You can set the slider to cache a shorter period of time and thus reduce the size of your offline cache.If you are the “owner” of a Shared Mailbox account, your best recourse is to turn off “Download shared folders,” as explained above or upgrade to Outlook 2016.
As an owner, however, you can at least help the users to whom you’ve granted folder access permissions.You can find her helping people online in Outlook Forums as well as in the Microsoft Answers and Tech Net forums.When someone “owns” a large Shared Mailbox account (e.g., having many large attachments), or if a user has extensive privileges to a Shared Mailbox account, the local online cache (OST file) of their Outlook client can grow to considerable size.Many people don't realize that with Windows updates, the updates for Microsoft Office are also "hidden." But it's not just the Office updates that can help speed up Outlook. In some cases, those updates can either break or cause problems with the communication between Outlook and Exchange.Or Microsoft might issue a patch to the application to resolve a speed issue or security hole.Outlook’s performance is affected by many things, including the amount of data it has to keep track of, any add-ons that are installed, how often it checks for new mail (checking more frequently can improve performance), and various other factors.