How can I parse the winmail.dat file?

Question

Simple question. I have a C# application that access an IMAP server using the AE.Net.Mail library to retrieve messages and attached files. Sometimes, when a message is sent from Outlook the attachments are contained in a file named winmail.dat. That is a file in the TNEF format.

Is there a library or any other way for my application to "unpack" theses files so I can get the attachments?

score 3 · Answer 1 · answered May 01 '14 at 17:36

3

I've just recently implemented TNEF support in MimeKit which is based on Microsoft's Exchange TNEF API, thus allowing full access to all of the data contained within.

answered May 01 '14 at 17:36

jstedfast

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score 2 · Answer 2 · answered Aug 22 '13 at 22:47

I had the same problem and ended up creating an entire email library for .NET called OpaqueMail.

It has support for parsing TNEF-encoded files (e.g. Winmail.dat) via its TnefEncoding class.

Check out this example.

// Instantiate a TNEF Encoding object to process the byte array "tnefEncoddedBytes".
TnefEncoding tnefEncoding = new TnefEncoding(tnefEncodedBytes);

// Loop through the TNEF-encoded attachments, outputting their names, content types, and sizes.
foreach (MimePart mimePart in tnefEncoding.MimeAttachments)
{
    Console.WriteLine("MIME Part Name: " + mimePart.Name);
    Console.WriteLine("MIME Part Content Type: " + mimePart.ContentType);
    Console.WriteLine("MIME Part Size: " + mimePart.BodyBytes.Length);
}

Downvoted to give preference to MimeKit answer. The above link no longer exists. — John, Nov 22 '22 at 23:30

score 1 · Accepted Answer · answered Jul 18 '12 at 15:52

1

I've found this tool that can be controled from the command line to extract attacheemnts, from a TNEF file, but I would really prefer a library that would run "in process".

answered Jul 18 '12 at 15:52

Mathieu Pagé

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I accepted my own answer because that is what I eventually used, but feel this is more an effective hack rather than a solution. – Mathieu Pagé Jul 28 '12 at 03:32

score 0 · Answer 4 · answered Jul 18 '12 at 15:59

0

A quick search leads to this : Yerase's TNEF Stream Reader

The project has source code, you can either reproduce it in C# or make a small C# (or better, C++/CLI) wrapper to use it.

answered Jul 18 '12 at 15:59

aybe

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score 0 · Answer 5 · answered Jul 21 '20 at 12:13

If its for Linux platform, then you could use tnef tool

TNEF

Usage to get the Body from winmail.dat : tnef -w --save-body winmail.dat Usage to extract only the attachments from winmail.dat file: tnef winmail.dat

Tnef extracts the Body/atatchments into our current directory where we are running this tool. Or else we could give the -C DIR, --directory=DIR to save them into the specified path

score -1 · Answer 6 · answered Jul 18 '12 at 16:04

-1

TnefReader Class could be of help.

answered Jul 18 '12 at 16:04

esskar

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1

I found this during my research. Unfortunately, the dll containing the Microsoft.Exchange namespace is not redistributable. – Mathieu Pagé Jul 19 '12 at 03:46

How can I parse the winmail.dat file?

6 Answers6