Body text garbled UTF-8/BASE64 combination

[Chris Green]

Hi there,

I have been experiencing a strange issue with either Mailscanner or Postfix 
which I am stuck with. I have built a machine as per the instructions at 
www.piratefish.org - essentially a Debian Sarge box with MailScanner, 
Postfix, SpamAssassin and ClamAV. Instructions have been followed verbatim. 
The vast majority of email is relayed with no issues at all, 90% of spam is 
canned and not a virus in sight. However, three times in the past three 
weeks we have received an email where the body text is completely garbled. 
This is probably 0.01% of incoming traffic.

I have posted an example pic at http://www.is-dept.com/download/garble.jpg - 
it's impossible to explain!

mail.err and mail.warn are both clean and neither of them indicates that the 
corrupted messages are any different to others that are delivered without an 
issue. The only pattern we have identified so far is that each affected 
message is encoded using UTF-8/BASE64 - but I can offer no evidence that 
this is unique amongst all mail being received.

I am in Hong Kong, so it is possible that locales are something to do with 
this issue. The only thing we have done so far is to run dpkg-reconfigure 
locales and add in Asian language locales and corresponding UTF-8 locales 
for all languages that the system is configured for. However, the problem 
continues. If anyone can suggest things that we could do to find out what 
the problem is we would be grateful.

Chris