Imap folders updating cached headers
I receive a lot of email, and I write a lot of email.
Outlook is seemingly not designed for heavy email use - when my number of messages in the inbox start to approach 2000 - this is when these problems occur on a regular basis.
If you want to turn off Cached Exchange Mode, repeat the steps, but clear Use Cached Exchange Mode.
By default, 12 months of your email is available offline, but you can control how much mail is kept offline.
Top of page Shared folders include Exchange Public Folders, Share Point folders, or another person's Exchange folders when you’re using Delegate Access.
However, when you are offline, you cannot read the message bodies or attachments.
If this preference is available for your email service and you select it, Outlook automatically updates your IMAP folders continuously.