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    <div class="moz-cite-prefix">On 16/06/2025 21:41, Martin Kellermann
      wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:ffef5effe9974f28a6e87ca67c667ddf@sk-datentechnik.com">
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        <p class="MsoNormal"><span style="mso-fareast-language:EN-US">Hi,<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-GB"
            style="mso-fareast-language:EN-US">It could be a
            password-protected zip attachment that prevents the virus
            scanner from opening and scanning the contents…<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-GB"
            style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-GB"
            style="mso-fareast-language:EN-US">regards<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-GB"
            style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-GB"
            style="mso-fareast-language:EN-US">MK</span></p>
      </div>
    </blockquote>
    <p>Thanks for the info.<br>
    </p>
    <p>I've managed to work it out by taking a copy of one of the
      problematic messages and progressively simplifying it and testing.
      What I've found is that the problem is triggered by having a
      multi-part message, where one or more parts contains multiple
      Content-Transfer-Encoding headers...<br>
    </p>
    <p>I've attached two files. If you compare them you'll see that the
      only difference between good.txt and bad.txt, is that bad.txt has
      an extra Content-Transfer-Encoding header within the first part of
      the multi-part message.<br>
    </p>
    <p>If you want to replicate my test, please run the following
      command on the server with Amavis, but replace <a class="moz-txt-link-abbreviated" href="mailto:user@example.com">user@example.com</a>
      with your own email address:</p>
    <pre>sendmail <a class="moz-txt-link-abbreviated" href="mailto:user@example.com">user@example.com</a> < bad.txt
</pre>
    <p>You should find bad.txt arrives with a subject of
      "***UNCHECKED*** Testing" (whereas good.txt has the unmodified
      subject of "Testing").</p>
    <p>Is this a bug that should be fixed in Amavis? Or ClamAV? Or is it
      expected that having an extra header like this makes the message
      invalid and therefore shouldn't be virus scanned?<br>
    </p>
    <p>Thanks,<br>
    </p>
    <p>Nick.</p>
    <p></p>
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