Under a default Exchange 2003 installation, all incoming
SMTP messages are written to a .eml file in the
folder “drive:\Program Files\Exchsrvr\Mailroot”.
This is the same partition to which your Exchange program files are also saved.
In some situations, moving the location of the SMTP Mailroot
folder can improve the overall performance of your Exchange system. Specifically,
Microsoft recommends that you locate your Mailroot folder
on a disk or array with substantial performance benefits.

To move the Mailroot folder in
Exchange 2003:

  • Open
    the Exchange System Manager.
  • Browse
    to Administrative Group > First Administrative Group > Servers >
    Name of your Exchange server > Protocols > SMTP.
  • Right-click
    your SMTP virtual server (usually named “Default SMTP Virtual
  • From
    the shortcut menu, choose Stop.
  • Right-click
    the same SMTP virtual server again
  • From
    the shortcut menu, choose Properties.
  • Select
    the Messages tab.
  • In the
    “Queue directory” field, provide the path to the new Mailroot folder.
  • Click
  • Right-click
    the SMTP virtual server
  • From
    the shortcut menu, choose Start.

Your changes will take effect immediately. You do not need
to restart the server or the Exchange services.