Blank Email Messages

[Kurt Bishop]

Hi,

Recently we have been getting reports of blank or mostly blank messages
being sent & received through our server.  We have tried to narrow dow the
problem and believe that MailScanner (or something related) is altering the
HTML message and the mail client cannot display it properly.

For example, I received a message the was blank except for the last line of
the sender's signature.  When doing a View Source on the message, I could
see that the HTML version of the message had been reduced to only include
what I could see on screen.  However, the plain text version of the message
was completely intact as the sender had written it.  Similarly, my
text-based mail client received a copy of this message which contained the
entire message body as expected.

The mail server logs showed the following entry when the message passed through:

Feb  6 05:27:26 mail MailScanner[26382]: Content Checks: Detected and will
disarm HTML message in j16ARH09027988

Here's a quick summary of our environment:

OS: Fedora Core 3
Kernel: 2.6.9-1.681_FC3
MailScanner: 4.36.4-1
Sendmail: 8.13.1-2
SpamAssassin: 3.0.1-0.FC3

These are the only MailScanner.conf entries I could find mentioning "disarm":

Allow Script Tags = disarm
Allow WebBugs = disarm

Here are some other MailScanner.conf entries that may be informational:

Dangerous Content Scanning = yes
Allow Partial Messages = no
Allow External Message Bodies = no
Find Phishing Fraud = yes
Allow IFrame Tags = no
Log IFrame Tags = no
Allow Form Tags = yes
Allow Object Codebase Tags = no
Convert Dangerous HTML To Text = no
Convert HTML To Text = no

Any suggestions would be greatly appreicated.  Thanks.

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