This is pretty simple. First, divide a message by parts. This header tells you some unique delimiter line:
Content-Type: multipart/alternative; boundary=001a11c361f6384c8e050046d84b
The delimiter is empty line followed by the value of "boundary".
Now, some headers are encoded with UTF-8, for example
Subject: =?UTF-8?B?15HXk9eZ16fXlA==?=
Three headers usually shown by a mail client will show:
From: אורון סולטן
To: oron sultan
Subject: בדיקה
Does it make sense to you?
Now, two parts at the end don't give any readable text, but I'll tell you how to read them. Look at those headers:
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: base64
It means that the plain-text content is HTML formatted, written in UTF-8 and then base64-encoded to form an ASCII text, not readable but tolerable by legacy mail systems, for extra reliability. Indeed, this is what is usually done instead of directly using UTF-8. To get original text, just base64-decode it. This is how:
http://msdn.microsoft.com/en-us/library/dhx0d524%28v=vs.110%29.aspx[
^].
Before using trial-and-error approach, just inspect the message and learn if you see some unknown terms. Here is what happened: the misleading information in your question was the story of your attempting of different encoding, which suggests that you did not have information on encoding and could not see what's in the messages. In fact, you have all the headers, which makes the problem quite trivial.
If you want a comprehensive interpretation of each and every detail of a message, you can use the open-source library OpenPOP.NET:
http://sourceforge.net/projects/hpop[
^].
This library is not very well written, but it thoroughly follows many standards like MIME, the information which is difficult to put together.
That's all.
—SA