Specify size of message to download when synchronizing folders
Click the Tools menu, point to Synchronize, and then click Offline Folder Settings.
Click Download Options.
Under Message size limit, select the Don't download messages larger than check box, and then enter a number of kilobytes that is the maximum size of message you want to download. Messages larger than this size are moved to the Large Messages folder on your server.
Note: If you want to receive some large messages but not others, select check boxes under Exceptions to specify which messages you want to download. For example, you can specify that messages from a certain person, such as your manager, are to be downloaded to your Inbox regardless of size.