DOCUMENT:Q128963  30-OCT-1999  [pcmail]
TITLE   :PC MAPI: How To Determine if a Mail Session Already Exists
PRODUCT :Microsoft Mail For PC Networks
PROD/VER:WINDOWS:3.0,3.2
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft Mail for PC Networks, versions 3.0, 3.2 
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SUMMARY
=======

When a you use the Microsoft Mail for PC Networks Simple Messaging Application
Programming Interface (Simple MAPI), you can fairly reliably determine if an
Microsoft Mail for Windows session is currently established. This information is
helpful due to the design of the Windows client and the inability to have
multiple simultaneous logins.

When it is largely unknown to the developer if a session will currently be
running, the following Microsoft Visual Basic version 3.0 code logic can be
helpful in reducing login errors.

MORE INFORMATION
================

The following code fragment is just one example of how to optimize a successful
login, without user intervention. This should be helpful for developers who want
to maximize their applications ability to login successfully.

NOTE: The message box calls are merely for clarity.

   Sub Form_Load ()
   ' ***                         ***
   ' *** Start sample login code ***
   ' ***                         ***

   rc& = MAPILogon(0&, "", "", 0&, 0&, lhSession&)
   If rc& <> SUCCESS_SUCCESS Then
     MsgBox "Login Error or session does not exist = " + Str(rc&)
     ' No session exists so lets pass info to create one
     rc& = MAPILogon(0&, "admin", "password", 0&, 0&, lhSession&)
     If rc& <> SUCCESS_SUCCESS Then
       MsgBox "Failure to login at all"
       End
     Else
       MsgBox "Successfully logged in as admin"
       ' Send important message
       rc& = MAPILogoff(lhSession&, 0&, 0&, 0&)
       End
     End If

   Else
     MsgBox "Mail session currently established"
     ' Send important message
     rc& = MAPILogoff(lhSession&, 0&, 0&, 0&)
   End If

   End
   End Sub
   '*** end code fragment ***'

Additional query words: 3.00 3.20 MS Mail Technical Reference

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Keywords          :  
Technology        : kbMailSearch kbZNotKeyword3 kbMailPCN320 kbMailPCN300
Version           : WINDOWS:3.0,3.2

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