DOCUMENT:Q101750  07-NOV-1999  [pcmail]
TITLE   :PC Ext: Overlay Files and How They Work
PRODUCT :Microsoft Mail For PC Networks
PROD/VER:WINDOWS:3.2
OPER/SYS:
KEYWORDS:

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Mail for PC Networks, version 3.2 
-------------------------------------------------------------------------------

SUMMARY
=======

The External Mail program (EXTERNAL.EXE) included with version 3.2 of Microsoft
Mail for PC Networks introduces overlay files to control different forms of
communication. These files are loaded into extended memory and introduce the
need for EXTERNAL.EXE to be stored on the local computer.

There are three overlay files, which provide the following functions:

 - The AYSNC.OVL file controls asynchronous communication.

 - The X25EICON.OVL file controls communication with the Eicon X.25 card.

 - The X25ATLAN.OVL file controls communication with the Atlantis X.25 card.

The External Mail program must load one of these overlay files because these
files contain shared code for the Mailer and Dispatch processes to distribute
messages on the network.

By loading this part of the process into extended memory, more postoffices can be
controlled by the External Mail program, thus getting around the memory
constraints of version 3.0 of the External Mail program.


Additional query words: 3.20

======================================================================
Keywords          :  
Technology        : kbMailSearch kbZNotKeyword3 kbMailPCN320
Version           : WINDOWS:3.2

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1999.