C# - Parse winmail.dat (TNEF)

The following c# codes demonstrate how to parse MAPI winmail.dat in email.

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.


Before you can use the following sample codes, you should download the EAGetMail Installer and install it on your machine at first. Full sample projects are included in this installer.

Install from NuGet

You can also install the run-time assembly by NuGet. Run the following command in the NuGet Package Manager Console:

Install-Package EAGetMail


If you install it by NuGet, no sample projects are installed, only .NET assembly is installed.

Add Reference

To use EAGetMail POP3 & IMAP Component in your project, the first step is “Add reference of EAGetMail to your project”. Please create or open your project with Visual Studio, then go to menu -> Project -> Add Reference -> .NET -> Browse..., and select EAGetMail{version}.dll from installation path, click Open-> OK, the reference will be added to the project, you can start to use it to retrieve email and parse email in your project.

add reference in c#/vb.net/managed c++/cli

.NET Assembly

Because EAGetMail has separate builds for .Net Framework, please refer to the following table and choose the correct dll.

Separate builds of run-time assembly for .Net Framework 1.1, 2.0, 3.5, 4.0, 4.5 and .Net Compact Framework 2.0, 3.5.

File .NET Framework Version
EAGetMail.dll Built with .NET Framework 1.1
It requires .NET Framework 1.1, 2.0, 3.5 or later version.
EAGetMail20.dll Built with .NET Framework 2.0
It requires .NET Framework 2.0, 3.5 or later version.
EAGetMail35.dll Built with .NET Framework 3.5
It requires .NET Framework 3.5 or later version.
EAGetMail40.dll Built with .NET Framework 4.0
It requires .NET Framework 4.0 or later version.
EAGetMail45.dll Built with .NET Framework 4.5
It requires .NET Framework 4.5 or later version.
EAGetMailCF20.dll Built with .NET Compact Framework 2.0
It requires .NET Compact Framework 2.0, 3.5 or later version.
EAGetMailCF35.dll Built with .NET Compact Framework 3.5
It requires .NET Compact Framework 3.5 or later version.

C# - Parse winmail.dat (TNEF) - Example

The following example codes demonstrate parsing winmail.dat - TNEF stream.

In order to run it correctly, please change email server, user, password, folder, file name value to yours.


To get full sample projects, please download and install EAGetMail on your machine.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.IO;

// Add EAGetMail namespace
using EAGetMail;

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

            // 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;
                        tatts = Mail.ParseTNEF(att.Content, true);
                    catch (Exception ep)
                    int y = tatts.Length;
                    for (int x = 0; x < y; x++)
                        Attachment tatt = tatts[x];
                        Console.WriteLine("winmail.dat: {0}", tatt.Name);
                Console.WriteLine("Attachment: {0}", att.Name);

        static void Main(string[] args)
            ParseEmail("c:\\my folder\\test.eml");



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