restricing few users from sending/receiving attachments in postfix and in sendmail

[John Francis]

On 23/01/06, Paul Howarth <paul at city-fan.org> wrote:
> On Sun, 2006-01-22 at 22:16 +0530, Ankush Grover wrote:
> My point was that it's virtually impossible to do this because
> attachments can be split up into multiple emails (thus getting around
> size restrictions) and can be included in (say) uuencode format in the
> message body rather than using a MIME-style attachment. In fact, that's
> how most people used to send large files over email before MIME came
> along.
>
> There must be an underlying reason why a ban on attachments is wanted
> (e.g. prevent sending confidential data, prevent sending viruses) and it
> might be better to attack the issue directly rather than in a roundabout
> way by trying to ban attachments.

Good point.  But the fact is that a simple filter (e.g. in postfix
header_checks) is sufficient to solve a good proportion of the
problem.  Average users do not have uuencode installed on their
Windows box let alone know what it is and how to use it.

Businesses may have a problem with attachments wasting bandwidth, time
and posing a threat to workplace harmony (e.g. sexual harrasment).  A
simple, easy to implement filter can "do the trick" nicely.

--
Kind regards,

John Francis