[Mimedefang] talking to and changing mimedefang in real-time...

David F. Skoll dfs at roaringpenguin.com
Tue Sep 3 09:48:01 EDT 2002

On Monday 02 September 2002 10:15, Tony Nugent wrote:

> Exactly what constitutes a "suspicious" message (or part)?

It depends on the virus scanner.  I have no idea. :-)

> Is there an easy way to trigger a function call based on a date or
> timeout alarm?  (It doesn't need to interrupt anything, just flag
> that the alarm/timeout has occurred when its status is next checked
> and then reset in the filter).

No, but it's probably cheap enough to do something like this in
your filter:

$LastDidTimerJob = 0;
$JobInterval = 86400; /* Once per day */
sub filter_begin {
	if (time() - $LastDidTimerJob > 86400) {
		$LastDidTimerJob = time();

However, it's probably unnecessary on machines which get a decent volume
of e-mail, because the Perl processes get killed after 100 messages anyway.
It's probably simpler to do one-shot initializations right in the filter
rules, outside any subroutine.

> What I have done allows me to change the runtime behaviour of the
> filter by literally sending it a message...

This is rather dangerous, unless you have a strong method of authentication
like gnupg.

> As for getting mimedefang to do cron jobs, all that is needed is to
> set up the action and a tigger in the filter, and periodically
> generate emails that make happen whatever you may want defang to do.

That's pretty cool...

>   Another example use:  for some reason you might want to have
>   defang deny relay to/from certain places/users and at specific
>   times, with the timing and actions controlled from a cron job or
>   manually with an administrative email.

As someone else wrote earlier, you can just do a "mimedefang reread"
to force the filter rules to be reloaded.  If you only do it a few times
a day, the performance hit is not too bad.

> Magic indeed... I have mimedefang doing all sorts of amazing things
> for me with the email here, it all works exactly as advertised :)

Thanks! :-)



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