Parse winmail.dat (TNEF/MAPI) in C#

In previous section, I introduced how to verify digital signature and decrypt email. In this section, I will introduce how to parse winmail.dat (TNEF stream) in C#.

Introduction

When an Outlook user composes and sends a message using either Rich Text Format or HTML Format, Outlook automagically generates a file, winmail.dat, and attaches it to the end of the email. The winmail.dat contains the rich text body and original attachments. To parse winmail.dat (TNEF stream) file, we should use ParseTNEF method.

Note

Remarks: All of examples in this section are based on first section: A simple C# project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference to your project.

[C# Example - Parse winmail.dat (TNEF stream)]

The following example codes demonstrate how to parse MAPI winmail.dat.

Note

To get the full sample projects, please refer to Samples section.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.IO;
using EAGetMail; // add EAGetMail namespace

namespace receiveemail
{
    class Program
    {
       private static void ParseEmail(string emlFile)
        {
            Mail oMail = new Mail("TryIt");
            oMail.Load(emlFile, false);

             if (oMail.IsEncrypted)
            {
                try
                {
                    // This email is encrypted, we decrypt it by user default certificate.
                    // you can also use specified certificate like this
                    // Certificate oCert = new Certificate();
                    // oCert.Load("c:\test.pfx", "pfxpassword",
                    //  Certificate.CertificateKeyLocation.CRYPT_USER_KEYSET);
                    // oMail = oMail.Decrypt( oCert );
                    oMail = oMail.Decrypt(null);
                }
                catch (Exception ep)
                {
                    Console.WriteLine(ep.Message);
                }
            }

            if (oMail.IsSigned)
            {
                try
                {
                    // This email is digital signed.
                    EAGetMail.Certificate cert = oMail.VerifySignature();
                    Console.WriteLine("This email contains a valid digital signature.");

                    // You can add the certificate to your certificate storage like this
                    // cert.AddToStore(
                    //    Certificate.CertificateStoreLocation.CERT_SYSTEM_STORE_CURRENT_USER,
                    //  "addressbook" );
                    // then you can use send the encrypted email back to this sender.
                }
                catch (Exception ep)
                {
                    Console.WriteLine(ep.Message);
                }
            }

            // Parse sender
            Console.WriteLine("From: {0}", oMail.From.ToString());

            // Parse to recipient
            MailAddress[] addrs = oMail.To;
            for (int i = 0; i < addrs.Length; i++)
            {
                Console.WriteLine("To: {0}", addrs[i].ToString());
            }

            // Parse cc
            addrs = oMail.Cc;
            for (int i = 0; i < addrs.Length; i++)
            {
                Console.WriteLine("To: {0}", addrs[i].ToString());
            }

            // Parse subject
            Console.WriteLine("Subject: {0}", oMail.Subject);

            // Parse Text/Plain body
            Console.WriteLine("TextBody: {0}", oMail.TextBody);

            // Parse Html body
            Console.WriteLine("HtmlBody: {0}", oMail.HtmlBody );

            // Parse attachments
            Attachment[] atts = oMail.Attachments;
            for (int i = 0; i < atts.Length; i++)
            {
                Attachment att = atts[i];

                // This attachment is in OUTLOOK RTF format(TNEF stream), decode it here.
                if (String.Compare(att.Name, "winmail.dat") == 0)
                {
                    Attachment[] tatts = null;
                    try
                    {
                        tatts = Mail.ParseTNEF(att.Content, true);
                    }
                    catch (Exception ep)
                    {
                        Console.WriteLine(ep.Message);
                        continue;
                    }
                    int y = tatts.Length;
                    for (int x = 0; x < y; x++)
                    {
                        Attachment tatt = tatts[x];
                        Console.WriteLine("winmail.dat: {0}", tatt.Name);
                    }
                    continue;
                }
                Console.WriteLine("Attachment: {0}", att.Name);
            }
        }

        static void Main(string[] args)
        {
            string curpath = Directory.GetCurrentDirectory();
            string mailbox = String.Format("{0}\\inbox", curpath);

            // If the folder is not existed, create it.
            if (!Directory.Exists(mailbox))
            {
                Directory.CreateDirectory(mailbox);
            }

            // Get all *.eml files in specified folder and parse it one by one.
            string[] files = Directory.GetFiles(mailbox, "*.eml");
            for (int i = 0; i < files.Length; i++)
            {
                ParseEmail(files[i]);
            }
        }
    }
}

Parse TNEF (winmail.dat) by DecodeTNEF method

In EAGetMail 4.5, a new method named DecodeTNEF is introduced. It is easier to parse TNEF attachment. Please have a look at the following example codes:

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.IO;
using EAGetMail; // add EAGetMail namespace

namespace receiveemail
{
    class Program
    {
       private static void ParseEmail(string emlFile)
        {
            Mail oMail = new Mail("TryIt");
            oMail.Load(emlFile, false);

             if (oMail.IsEncrypted)
            {
                try
                {
                    // This email is encrypted, we decrypt it by user default certificate.
                    // you can also use specified certificate like this
                    // Certificate oCert = new Certificate();
                    // oCert.Load("c:\test.pfx", "pfxpassword",
                    //  Certificate.CertificateKeyLocation.CRYPT_USER_KEYSET);
                    // oMail = oMail.Decrypt( oCert );
                    oMail = oMail.Decrypt(null);
                }
                catch (Exception ep)
                {
                    Console.WriteLine(ep.Message);
                }
            }

            if (oMail.IsSigned)
            {
                try
                {
                    // This email is digital signed.
                    EAGetMail.Certificate cert = oMail.VerifySignature();
                    Console.WriteLine("This email contains a valid digital signature.");

                    // You can add the certificate to your certificate storage like this
                    // cert.AddToStore(
                    //    Certificate.CertificateStoreLocation.CERT_SYSTEM_STORE_CURRENT_USER,
                    //  "addressbook" );
                    // then you can use send the encrypted email back to this sender.
                }
                catch (Exception ep)
                {
                    Console.WriteLine(ep.Message);
                }
            }

            // Decode winmail.dat (TNEF) and RTF body automatically
            oMail.DecodeTNEF();

            // Parse sender
            Console.WriteLine("From: {0}", oMail.From.ToString());

            // Parse to recipient
            MailAddress[] addrs = oMail.To;
            for (int i = 0; i < addrs.Length; i++)
            {
                Console.WriteLine("To: {0}", addrs[i].ToString());
            }

            // Parse cc
            addrs = oMail.Cc;
            for (int i = 0; i < addrs.Length; i++)
            {
                Console.WriteLine("To: {0}", addrs[i].ToString());
            }

            // Parse subject
            Console.WriteLine("Subject: {0}", oMail.Subject);

            // Parse Text/Plain body
            Console.WriteLine("TextBody: {0}", oMail.TextBody);

            // Parse Html body
            Console.WriteLine("HtmlBody: {0}", oMail.HtmlBody );

            // Parse attachments
            Attachment[] atts = oMail.Attachments;
            for (int i = 0; i < atts.Length; i++)
            {
                Attachment att = atts[i];

                Console.WriteLine("Attachment: {0}", att.Name);
            }
        }

        static void Main(string[] args)
        {
            string curpath = Directory.GetCurrentDirectory();
            string mailbox = String.Format("{0}\\inbox", curpath);

            // If the folder is not existed, create it.
            if (!Directory.Exists(mailbox))
            {
                Directory.CreateDirectory(mailbox);
            }

            // Get all *.eml files in specified folder and parse it one by one.
            string[] files = Directory.GetFiles(mailbox, "*.eml");
            for (int i = 0; i < files.Length; i++)
            {
                ParseEmail(files[i]);
            }
        }
    }
}

Next Section

At next section I will introduce how to convert email to HTML page and display it in Web browser.

Appendix

Comments

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