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Article ID: 310212 - View products that this article applies to.
This article was previously published under Q310212


This article describes how to use the Collaboration Data Objects (CDO) for Windows 2000 library (Cdosys.dll) to send an e-mail message with attachments. You can send text or HTML or a Web page in the body of the e-mail message by using the local SMTP server or by using a smart host server in Microsoft Visual C#.

Note The Cdosys.dll library is also known as CDOSYS.


To use CDOSYS as described in the "Summary" section, follow these steps:
  1. Start Microsoft Visual Studio.
  2. On the File menu, click New, and then click Project.
  3. Under Project Types, click Visual C#, and then click Console Application under Templates. By default, Program.cs is created.

    Note In Microsoft Visual C# .NET 2003, Visual C# is changed to Visual C# Projects. By default, Class1.cs is created.
  4. Add a reference to the Microsoft CDO For Windows 2000 Library. To do this, follow these steps:
    1. On the Project menu, click Add Reference.
    2. On the COM tab, locate Microsoft CDO For Windows 2000 Library.

      Note In Visual C# .NET 2003, click Select.
    3. To accept your selections, click OK in the Add References dialog box.

      If you receive a dialog box to generate wrappers for the libraries that you selected, click Yes.
  5. In the code window, replace all the code with the following code:
    namespace CdoSys
    	using System;
    	class Class1
    		static void Main(string[] args)
    				CDO.Message oMsg = new CDO.Message();
    				CDO.IConfiguration iConfg; 
    				iConfg = oMsg.Configuration;
    				ADODB.Fields oFields;
    				oFields = iConfg.Fields;       
    				// Set configuration.
    				ADODB.Field oField = oFields[""];
    				//TODO: To send by using the smart host, uncomment the following lines:
    				//oField.Value = CDO.CdoSendUsing.cdoSendUsingPort;
    				//oField = oFields[""];
    				//oField.Value = "smarthost";
    				// TODO: To send by using local SMTP service. 
    				//oField = oFields[""];
    				//oField.Value = 1;  
    				// Set common properties from message.
    				//TODO: To send text body, uncomment the following line: 
    				//oMsg.TextBody = "Hello, how are you doing?";
    				//TODO: To send HTML body, uncomment the following lines:
    				//String sHtml;
    				//sHtml = "<HTML>\n" + 
    				//	"<HEAD>\n" +
    				//	"<TITLE>Sample GIF</TITLE>\n" +
    				//	"</HEAD>\n" +
    				//	"<BODY><P>\n" + 
    				//	"<h1><Font Color=Green>Inline graphics</Font></h1>\n" +
    				//	"</BODY>\n" + 
    				//	"</HTML>";
    				//oMsg.HTMLBody = sHtml;
    				//TOTO: To send WEb page in an e-mail, uncomment the following lines and make changes in TODO section.
    				//TODO: Replace with your preferred Web page
    				//	CDO.CdoMHTMLFlags.cdoSuppressNone, 
    				//	"", ""); 
    				oMsg.Subject = "Test SMTP";  
    				//TODO: Change the To and From address to reflect your information.                       
    				oMsg.From = "";
    				oMsg.To = "";
    				//ADD attachment.
    				//TODO: Change the path to the file that you want to attach.
    				oMsg.AddAttachment("C:\\Hello.txt", "", "");
    				oMsg.AddAttachment("C:\\Test.doc", "", "");
    			catch (Exception e)
    				Console.WriteLine("{0} Exception caught.", e);
  6. Where TODO appears in the code, modify the code as indicated.
  7. To build and run the program, press F5.
  8. Verify that the e-mail message has been both sent and received.


For more information about Microsoft Office development with Visual Studio, see the following Microsoft Developer Network (MSDN) Web site:
For additional information about how to use CDOSYS, click the following article numbers to view the articles in the Microsoft Knowledge Base:
310221 How to use the Cdosys.dll library to embed a message in a new message by using Visual C# .NET
310224 How to use the Cdosys.dll library to process mail in the Drop directory by using Visual C# .NET
310225 How to use the Cdosys.dll Library to save a message to a file by using Visual C# .NET


Article ID: 310212 - Last Review: July 30, 2008 - Revision: 4.0
  • Microsoft Visual C# 2008 Express Edition
  • Microsoft Visual C# 2005
  • Microsoft Collaboration Data Objects 2.0
  • Microsoft ActiveX Data Objects 2.5
  • Microsoft ActiveX Data Objects 2.6
  • Microsoft ActiveX Data Objects 2.7
  • Microsoft Internet Information Services 6.0
  • Microsoft Internet Information Services 5.0
kbsweptvs2008 kbcode kbhowto KB310212