Score on attachments

[Rick Cooper]

Max Kipness wrote:
>> You do not say what your MTA is but I have to assume postfix or
> sendmail (I use exim) have some kind of mime type blocking as does
> exim so it's easy to either reject or dev/null any email that has a
> .scr file 
>> attached (or any other type for that matter) and it never get's to
> MailScanner or the user. I dump about 1/2 dozen different file types
> that should never be sent (un
>> archived) including .src, right at the MTA level
>> 
>> Rick
> 
> Good point there. I use Sendmail.
> 
> For the SCR files there really is not a legimate reason to send them
> so you would assume the whole email should be trashed.  I'm going to
> look into this. But what if the SCR is zipped? That is the way I'm
> getting them.
> 
> Max

The answer is yes Exim can, but you have to write a rather simple script to
be called on the file to handle the processing of files inside archives. I
only block the those that are outside archives and let mailscanner handle
those that are inside as it seems cleaner to me. I don't think you want to
hold up the MTA while something unpacks all the attachments, and their
children looking for a specific file type, better to let MailScanner do that
in the background

Mailscanner, use the archive file name/type rules and set to deny. You can
see what happens if you set deliver cleaned to no, I don't know if that
applies to messages with files removed or not.