Gaetan
Here is the header info from a message with your test.txt.zip file attached that was sent from & to my account on a SME server, note that SME did not block the message.
------=_NextPart_000_0007_01D010F4.AB35F890
Content-Type: application/octet-stream;
name="Test.txt.zip"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename="Test.txt.zip"
UEsDBBQACAAIAP1UhUUAAAAAAAAAAAAAAAAIABAAVGVzdC50eHRVWAwAd32BVG59gVT1ARQAe797
f0hqcQkXAFBLBwiBv2bKCgAAAAgAAABQSwECFQMUAAgACAD9VIVFgb9mygoAAAAIAAAACAAMAAAA
AAAAAABApIEAAAAAVGVzdC50eHRVWAgAd32BVG59gVRQSwUGAAAAAAEAAQBCAAAAUAAAAAAA
Note the pertinent part of the file signature or magic is
UEsDBBQAC
The two zip signatures that SME will detect when selected are:
UEsDBAoAA
UEsDBBQAA
The file signature from your zip test file does not match either of the signatures in the mailpatterns database, so that is why the message is not being rejected, even though it has a zip file attachment.
It seems to me that the signature needs to be added to the mailpatterns database eg as another type of zip OSX variant file
You can follow the instructions in the Howto to achieve this
http://wiki.contribs.org/Virus:Email_Attachment_Blocking#Enabling_or_disabling_patternsComparing it to those other zip files I received earlier today, they are different again,
Header info from recently received messages with zip attachments:
Content-Disposition: attachment; filename="Internal_Only_pdf.zip"
UEsDBBQDA
Content-Disposition: attachment; filename="STD_261.zip"
UEsDBBQDA
So perhaps that signature also needs to be added to the mailpatterns database as a zip variant 3 type
This will add these signatures to the mailpatterns database
/sbin/e-smith/db mailpatterns set ZIPVOSX pattern Body UEsDBBQAC Description "Zip archive data, created on OSX" Glob yes LineStart yes Status enabled
/sbin/e-smith/db mailpatterns set ZIPV3 pattern Body UEsDBBQDA Description "Zip archive data, variant 3" Glob yes LineStart yes Status enabled
signal-event email-update