Outlook always updating cached messages
Most of the reasons to work offline are eliminated when you use Cached Exchange Mode.
The lack of a network connection is almost transparent to you because you can continue to work with your items whether you are connected to the computer that is running Exchange.
Outlook remembers up to 1000 email addresses you've used in the past, even if you have never stored them as Contacts. One benefit is that you can easily retrieve email addresses you have used just by typing the first few letters.
A drawback is that as you update your contacts, the Auto Complete name cache file remains static.
About: There are two types of Outlook data files used by Outlook for Windows.
An Outlook Data File (.pst) is used for most accounts.
How can I configure it so that it will directly download the message in full without clicking on it first?
Up until Outlook 2007, by default an IMAP account will indeed be set to “Download headers only”.
If a file gets damaged or lost, you can use Time Machine to browse through the backups and recover the copy of the file.
I upgraded to Outlook 2010 and I have the feeling that my IMAP account performance has become slower.
Especially when switching folders, it takes quite a while for Outlook to become active again and shows “Not Responding” in the Title Bar.
When your connection to the Exchange computer is interrupted, you can continue to work with your data.
When a connection is restored, changes are automatically synchronized, and the folders and items on the server and on your computer are identical again.