converting TNEF attachments?

[Nik777]

Hi All,

I have switched our email from an old Sendmail/imapd machine to a new 
Kolab machine. All users are extremely complimentary about the 
performance and robustness of the new system.

However, I had tnefclean installed and working on the old server, and am 
now looking for a way to implement the same on Kolab. With tnefclean, 
those nasty WINMAIL.DAT attachments were converted into regular MIME 
attachments, so that non-Outlook users (eg Thunderbird) could see and 
read them.

I see that Kolab's amavisd does load Convert::TNEF at startup. However, 
it seems this is just used so that such attachments are scanned, rather 
than converting them to MIME.

The tnefclean program is a perl script which can be run as a filter, 
copying its modified output to stdout. So in my Sendmail configuration, 
I simply added a rule to procmailrc which filtered all mail through 
tnefclean.pl.

So my question is: how can I easily get Kolab's postfix server to filter 
all mail through tnefclean? I'm hoping that one of postfix's filter 
options will be appropriate, although all documentation I've read on 
that so far seems to indicate that I need to "reinject" filtered emails 
back into a separate instance of postfix. Since tnefclean is simply 
modifying a streamed email, I'm not sure if this would work?

I notice that there is procmail in my Kolab installation, but it seems 
unused, and the only articles I found regarding enabling it stated I had 
to put entries into my config files for all Kolab users. This is not 
viable with our installation, as new users are created regularly by 
non-technical office admin staff using the Kolab web interface. They are 
not in a position to modify Kolab config files.

It also seems that Sieve is not capable of calling an external filter 
program? Am I correct on this?


Can anyone advise on how I should do this, or on where I should start 
testing?

Many thanks in advance for all suggestions.

Cheers!
Nik