We have a site that provides email to several remote sites via Outlook Web Access. These remote users can send email fine to any address, except, when they send to a user on the server providing the OWA they appear in a Chinese font. This is not just one remote station but several over several sites all using different ISP's
The server is running Windows Server 2003 sp2 and Exchange 2003 sp2, they also use Exclaimer 4.11 and the details and text that it adds to the email comes through fine. It's just the body of the mail that is in Chinese.
They also run GFI Mail Essentials v14 & Mail Security v10
It may be related but forcing the client to download the S-MIME control appears randomly to fix this for a day or so.... sometimes.
The server has the S-MIME hotfix applied to allow Vista to use OWA.
I've included the mail headear of one such email in case it helps.
Microsoft Mail Internet Headers Version 2.0
Received: from mail pickup service by xxxx.xxxx.local with Microsoft SMTPSVC;
Tue, 7 Jul 2009 14:53:23 +0100
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.4325
Subject: RE: Chinese emails
Date: Tue, 7 Jul 2009 14:52:42 +0100
Thread-Topic: Chinese emails
From: "Test Account" <firstname.lastname@example.org>
To: "Test Recipient" <email@example.com>
X-OriginalArrivalTime: 07 Jul 2009 13:53:23.0453 (UTC) FILETIME=[4B47EAD0:01C9FF0A]