Q128963: PC MAPI: How To Determine if a Mail Session Already Exists

Article: Q128963
Product(s): Microsoft Mail For PC Networks
Version(s): WINDOWS:3.0,3.2
Operating System(s): 
Keyword(s): 
Last Modified: 30-OCT-1999

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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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