If an Exchange client supports Remote Mail, it will allow you to work
   interactively with your mail server. This means manually logging in,
   hand-selecting the messages you want to move, copy, or delete, and
   then transferring.
   
   Normally, when you select "Deliver now using..." or if you set up your
   client for a LAN or other continuous connection, it runs the chosen
   service, logs in, moves all of your mail from the server to your
   Inbox, transmits anything in your Outbox, then disconnects. This is
   quite blatant and quite efficient. Remote Mail however, in the same
   Tools menu, lets you fully control mail delivery, provided you enabled
   Remote Mail in your clients.
   
   NOTE: In the original Exchange product, you had to use several buttons
   (Connect, Update Headers, Transfer Mail) to complete a remote task.
   The Windows Messaging update combines these three buttons into one
   (Transfer Mail). This one click will send anything in your Outbox,
   download anything you marked in the headers list, and update the
   headers list, all at once. It will NOT copy, move, or delete mail
   unless you explicitly marked any mail for doing do. This is much
   simpler and it takes nothing away from Remote Mail functionality!
   
   In MS-Mail, using Remote Mail depends on your connection type. You can
   set different Remote Mail options for LAN and for Dial-up networking
   sessions, so if it's on the LAN it'll work one way, and if it's on a
   phone line it will work another. You will only get a Remote Mail
   choice for MS-Mail if you enabled it for whatever your current
   connection is. Slow machines will benefit if you enable Remote Mail
   for LAN connections, as the mail checks eat up processor time and load
   down the system.
   
   Internet Mail only has one place for defining the Remote Mail
   behavior: The Connection tab in Internet Mail properties. You either
   enable Remote Mail, or disable it and check for mail every so often
   (15 minutes by default). The latter works best if you have a POP3
   server right on your LAN, otherwise, keep Remote Mail enabled. You can
   always do a Deliver Now if you want to do a batch mail delivery.
   
   CIS Mail always has Remote Mail enabled, but you can instruct it to
   dial out and check every so often as well.
   
   BillNet (TM) Remote Mail is also always enabled, and it will log you
   in to BillNet when you perform a delivery, either using Remote Mail,
   or Deliver Now.

     * 10.3.1. How can I keep mail on the server? 
       
   Enable Remote Mail for whatever client you're using. This will let you
   view all the mail in your server by selecting "Update Headers", and
   hand-select pieces of mail for copying, moving, or deleting.
   
   To keep mail on the server, select the option "Mark to receive a copy"
   rather than "Mark to receive".
   
   Remote Mail always keeps a local copy of the mail list, so you needn't
   be attached to the server to maintain your list. It will attach to the
   server only if you tell it to, or if you perform any transfers, and it
   will update the list whenever a transfer occurs. It distinguishes read
   mail from unread mail by bolding unread mail.