[exim] MIME extension filter fails to catch filename

Hello everyone,


I currently see fishing mails with .zip mime extension that should get
filtered by a content filter but do not.

Is is a cyrillic filename with .jpg.zip extension (Скан квитанции.jpg.zip):

--------------DAA7D016D126136E9026DA5F
Content-Type: application/zip;
    name="=?windows-1251?B?0erg7SDq4ujy4O326OguanBnLnppcA==?="
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
    filename="=?windows-1251?B?0erg7SDq4ujy4O326OguanBnLnppcA==?="

It does not get blocked by the filter below while that usually catches .zip:

   deny
         condition = $acl_m_datamimefilter
         condition = ${if match \
                         {${lc:$mime_filename}} \

{\N(\.bat|\.btm|\.cmd|\.com|\.cpl|\.dll|\.exe|\.lnk|\.msi|\.pif|\.prf|\.reg|\.scr|\.vbs|\.url|\.zip|\.7z|\.jar|\.ace|\.docm|\.rar|\.cab|\.xlsx|\.xls|\.docx|\.doc)$\N} 
\
                         {1}{0}}
         message = Blacklisted file extension detected in "$mime_filename".
         log_message = DENY: Blacklisted extension ("$mime_filename")

Also the demime that was in place earlier did not catch those:

   drop message = This message contains an attachment of a type which we 
do not accept (.$found_extension)
        demime = 
bat:com:pif:prf:scr:vbs:exe:zip:doc:xls:docx:xlsx:cab:docm:rar:docm:ace:jar:7z
        condition = $acl_m_datamimefilter

Does anyone know why this filename is not being catched by the filters?



Best regards,

Franz Georg Köhler