Remote Server returned '550 5.6.0 CAT.InvalidContent.Exception: InvalidCharsetException, Character set name (WIN1250) is invalid or not installed.; cannot handle content of message with InternalId 1249835483212, InternetMessageId

Hello,

Please help. I have Exchange 2013 CU3 with multi-role of the CAS/MBX on Windows 2012 R2 servers. From one specific addresses from the internet, Exchange rejects the message, and to the sender returns NDR:

Remote Server returned '550 5.6.0 CAT.InvalidContent.Exception: InvalidCharsetException, Character set name (WIN1250) is invalid or not installed.; cannot handle content of message with InternalId 1249835483212, InternetMessageId <messageID>.'

Received: from hostname (IP.33) by hostname

 (10.143.66.40) with Microsoft SMTP Server id 15.0.775.38; Wed, 15 Jan 2014

 16:05:21 +0100

X-AuditID: 0ae6cdd1-f79976d000000e60-ee-52d6a3b000f1

Received: from hostname (hostname [IP.210])  by

hostname (Symantec Mail Security) with SMTP id

 34.6B.03680.0B3A6D25; Wed, 15 Jan 2014 16:05:20 +0100 (CET)

Received: (qmail 18641 invoked from network); 15 Jan 2014 16:05:20 +0100

Received: from unknown (HELO matrix) (IP.86)  by IP.60 with

 SMTP; 15 Jan 2014 16:05:20 +0100

Date: Wed, 15 Jan 2014 16:05:20 +0100

From: <sender@domain.xx>

Sender: <sender@domain.xx>

Reply-To: <sender@domain.xx>

To: <recipient@domain.xx>

X-Mailer: Blat v2.2.2, a Win32 SMTP/NNTP mailer http://www.blat.net

Message-ID: <messageID>

Subject: =?WIN1250?B?Q1NCIE9iamVkbuF2a2EgSCBwcm8gS29zdGVsZWNr6SB1emVuaW55?=

  =?WIN1250?Q?_a=2Es=2E_=2800000082=29?=

MIME-Version: 1.0

Content-Type: multipart/mixed;

        boundary="=_BlatBoundary-QvNYMX6xOBMtYJX5A524P"

X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprCKsWRWlGSWpSXmKPExsVydXrwJd0Ni68FGWx8ZWSx49tfFgdGjwUv

        /7MFMEZx2aSk5mSWpRbp2yVwZXxf9I6l4LFKRce3P8wNjJuVuxg5OSQETCQ6d15igrDFJC7c

        W8/WxcjFISRwkFFi9rKDYAkhAQ+Js2/aWCDsHInDC5tZQWwWAVWJL0u3M4PYbAKiEn0TmsHq

        hQXEJR7v+MoKUS8pMan9KViNiICIxLWLmxkhljlL7Dm4BMzmFbCQuLp7OyNEb6lE27JZTBBx

        QYmTM5+A7WUW8JP4eGI+2wRG/llIUrOQpCBsbYllC18zQ9iaEnNn3meHsG0kum5cYZrFyAFk

        u0u86LGECCtKbD6wm3UBI/sqRrHcxMwcIwO9xPSi/LTUohK9vMT0xLz8TYzAUOZ6dvbiDsZv

        7RaHGAU4GJV4eCfPuRYkxJpYVlyZe4hRBWjQow2rLzBKseTl56UqifCuXwCU5k1JrKxKLcqP

        LyrNSS0+xCjNwaIkzut2al2QkEB6YklqdmpqQWoRTJaJgx1EcJ5irJQS5+1eBDRAoLggMTej

        NK8EpkpKjHfHmytBQvxIEkmlOdlSMrwMMy8HCYkiieellhfnpJYAmVIKvFtBuiSRZItLiwsy

        kzPzS4vjS4vgCekSoxkHC9D0yuL4xJyc/PL4VFCYCIF9JSXMy8jAwCDEA3RzbmYJxEEwjVIN

        jKyxVxKUnvl5SjeaXNrE99OPh1GRSfDMVt3sjYuYF/Jo9B+xOcpZvXM32xu1jMUOv94tYjuy

        +5NUcsVdCwWfO6tmOU9tjdj1Jqx1S0S884+oGEfBKvatTRxhgi/Pz34+W6164b5az/kMB/dU

        ZQgqVPuYeV02cKgO+jo9ptRJ3zBj9a/CdYKblViKMxINtZiLihMBUZkBeScDAAA=

Return-Path: sender@domain.xx

I found the solution for this error for Exchange 2010 SP1 http://support.microsoft.com/kb/2536702/en-us , but it does not work in Exchange 2013 CU3. Nowhere on the Internet I could not find a way to solve this.

Thank you for the help