subscription problems due to broken subject line

Hello everyone!

I have a problem, that some users cant subscribe to the mailinglist, because
the freemail-provider of these users(it's a german freemailer GMX), "breaks"
the Subject line - look at this mess! :

------------------
Return-Path: <[email protected]>
X-Original-To: [email protected]
Delivered-To: [email protected]
Received: by vovka.de id AEBFD22870; Wed,  3 Aug 2005 13:23:24 +0200 (CEST)
X-From_:[email protected]  Wed Aug  3 13:23:24 2005
X-Original-To: [email protected]
Delivered-To: [email protected]
Received: from mail.gmx.net (mail.gmx.de [213.165.64.20])
	by vovka.de (Postfix) with SMTP id 0CAD022862
	for <[email protected]>; Wed,  3 Aug 2005 13:23:23 +0200 (CEST)
Received: (qmail 31339 invoked by uid 17); 3 Aug 2005 11:23:23 -0000
Received: from 195.37.76.167 by www28.gmx.net with HTTP;
	Wed, 3 Aug 2005 13:23:23 +0200 (MEST)
Old-Date: Wed, 3 Aug 2005 13:23:23 +0200 (MEST)
From: [email protected]
To: [email protected]
MIME-Version: 1.0
Subject: =?ISO-8859-1?Q?subscribe?=
X-Priority: 3 (Normal)
X-Authenticated: #10973817
Message-ID: <[email protected]>
X-Mailer: WWW-Mail 1.6 (Global Message Exchange)
X-Flags: 0001
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
X-Diagnostic: Already on the subscriber list
X-Diagnostic: [email protected]
X-Envelope-To: berlin-request
Date: Wed,  3 Aug 2005 13:23:24 +0200 (CEST)
--------------------------

The subject line is "Subject: =?ISO-8859-1?Q?subscribe?=" instead of
the "Subject: subscribe".

It seems to be the problem only of this provider.

What can be done in such case?

Other software(Mozilla Mail /Thunderbird) do not worry about this "=?ISO-8859-1?Q? ... ?="-line
and displays the Subject-Line correctly.

Ist it a kinda new RFC-Standard for the Subject-lines - to put the encodings information in it?
Or are the programmers of this freemailer simply stupid?



Greetings


Vladimir-