The folders that I expect do not download.
Microsoft Outlook might be displaying only the folders you subscribed to.
I can't find my deleted messages to restore them.
You might be in a view that does not show deleted messages.
My message flags have disappeared.
IMAP does not support message flags, so you cannot send or receive messages with flags on them. You can set flags on messages that stay in your Inbox or in another folder, for example, to remind you to follow up.
I can't see the contents of messages by using AutoPreview.
You are viewing messages that have only headers downloaded. You need to download the body of the message.
How?
My rules don't work on IMAP messages.
Any rules you have set up to work on text in the body of a message will not work for IMAP messages that have only headers downloaded. You need to download the entire message for the rule to work.
How?