DOCUMENT:Q278321  27-AUG-2001  [exchange]
TITLE   :HOWTO: Force a Particular Internet Encoding by Using MAPI
PRODUCT :Microsoft Exchange
PROD/VER::5.5
OPER/SYS:
KEYWORDS:

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

 - Microsoft Exchange Server, version 5.5 
 - Microsoft Exchange 2000 Server 
-------------------------------------------------------------------------------

SUMMARY
=======

You can use the Messaging Application Programming Interface (MAPI) property
PR_INETMAIL_OVERRIDE_FORMAT (0x59020003) to force the Exchange Internet Mail
Service (IMS) to use a particular encoding scheme for the message body and
attachments. This per-message property can be set in both Collaboration Data
Objects (CDO) and Extended MAPI code.

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

The possible values of PR_INETMAIL_OVERRIDE_FORMAT, which correspond to the Send
Options settings in Microsoft Outlook, are as follows:

+---------------------------------------------------------------------------------------------+
| Value | Outlook Setting | Message Format                  | Attachment Encoding             | 
+---------------------------------------------------------------------------------------------+
| 0     | Unknown         | Depends on default IMS settings | Depends on default IMS settings | 
+---------------------------------------------------------------------------------------------+
| 1     | MIME            | MIME                            | Base64                          | 
+---------------------------------------------------------------------------------------------+
| 2     | UUEncode        | Text                            | UUEncode                        | 
+---------------------------------------------------------------------------------------------+
| 3     | BINHEX          | Text                            | BinHex                          | 
+---------------------------------------------------------------------------------------------+

Sample Code for CDO
-------------------

The following CDO Microsoft Visual Basic code sends a MIME message with two
attachments, encoded with Base64:

   ' Reference to Microsoft CDO 1.21 library.
   Private Sub SendMail_Click()
       Dim objSession As MAPI.Session
       Dim objMessage As MAPI.Message
       Dim objAttachments As MAPI.Attachments
       Dim objAttachment As MAPI.Attachment
       Dim objRecipients As MAPI.Recipients
       Dim objRecipient As MAPI.Recipient
          
       Dim Recipient As String
       Dim MsgSubject As String
       Dim EncodingFlag As Integer
       Dim bmpFile As String
       Dim txtFile As String
       Dim FileLocation As String
       
       'TODO: Modify the following to appropriate values.
       Recipient = "myaccount@hotmail.com"
       EncodingFlag = 1 'Use MIME encoding
       bmpFile = "mybmp.bmp"
       txtFile = "mytxt.txt"
       FileLocation = "c:\"
       
       MsgSubject = "Test Encoding: " & EncodingFlag
       
       On Error GoTo Err
       
       Set objSession = CreateObject("MAPI.Session")
       
       objSession.Logon showdialog:=True
       
       Set objMessage = objSession.Outbox.Messages.Add(MsgSubject, "body")
           
       Set objAttachments = objMessage.Attachments
       objAttachments.Add txtFile, 0, CdoFileData, FileLocation & txtFile
       objAttachments.Add bmpFile, 0, CdoFileData, FileLocation & bmpFile
       
       Set objRecipients = objMessage.Recipients
       Set objRecipient = objRecipients.Add
       
       objRecipient.Name = Recipient
       objRecipient.Resolve
           
       objMessage.Fields.Add &H59020003, EncodingFlag
       
       objMessage.Update
       
       objMessage.Send True
       
   Err:
       If Err.Number Then
           Debug.Print Err.Number & ": " & Err.Description & "::" & Err.Source
           Err.Clear
       End If
       
       If Not objSession Is Nothing Then objSession.Logoff

   End Sub

An issue in the CDO ReadFromFile method can interfere with the encoding process.
If ReadFromFile is used, CdoPR_ATTACH_LONG_FILENAME needs to be set on the
attachment. For more information, see the following article in the Microsoft
Knowledge Base:

   Q278358 PRB: File Attached Via CDO Has Incorrect Filename

Headers for MAPI
----------------

You can use this property from Extended MAPI code as well; the following #defines
will help:

   #define PR_INETMAIL_OVERRIDE_FORMAT PROP_TAG(PT_LONG,0x5902)

   #define ENCODEDONTKNOW 0
   #define ENCODEMIME 1
   #define ENCODEUUENCODE 2
   #define ENCODEBINHEX 3


Important Notes
---------------

The encoding specified in PR_INETMAIL_OVERRIDE_FORMAT take effect only if the IMS
does not encode the message as Rich Text/TNEF. For information on preventing the
use of transport-neutral encapsulation format (TNEF), see the following
article:

   Q149203 XFOR: Preventing Winmail.dat From Being Sent Over IMC

The information in this article applies only to mail that is sent through the
Exchange Internet Mail Connector (IMC). It does not apply to mail that is sent
through the Outlook Internet Mail Provider.



REFERENCES
==========

For more information on Outlook and message encodings, see the following
article:

   Q268547 OL2000: Information About Outlook and Encoded Messages

Additional query words:

======================================================================
Keywords          :  
Technology        : kbExchangeSearch kbExchange550 kbZNotKeyword2 kbExchange2000Search kbExchange2000Serv
Version           : :5.5
Issue type        : kbhowto

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

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 2001.