At 1:41 PM -0500 2/21/2000, John R Levine wrote:
>My autoresponders remember all the addresses they've written
>to, and will not send more than five responses per hour to any single
>address, dropping responses over that limit.
What do you use to implement mailbots? Perl? procmail?
>There's nothing you can put in an outgoing
>message that will reliably let you detect an autoresponse, too many
>autoresponses completely discard the message they're responding to so
>there's no body nor any copy of the subject line.
Yeah. My favorite recent braindamage was a site that sent back errors
by simply reflecting the message back to the "to" address. the only
headers changed were the addition of Received lines and a new
Message-ID -- so I couldn't even trap the loop based on duplicate
sendings. This started a really gnarly mail loop on a list before I
tracked it down, and I'm still unsure how to protect my system from
it other than banning those domains (FWIW, it's an aged version of a
microsoft mail gateway...).
>Wow. I'm amazed that you found two mail systems robust enough to handle 90MB
>messages, but broken enough to get into a loop like that.
The mail systems weren't broken. On the far side, it was a guy with
your typical "last minute untested" broken vacation message, and on
my side, it was majordomo, which doesn't rate limit or any other
limit on return messages.
> > So this is what I'd suggest. If nothing else, track the number of
>> rejected messages and if it spikes or goes over some chosen value,
>> then Do Something.
>
>You got it.
Yeah. In procmail, the 'easy' way is to use the formail address cache
mechanism iwth a rather small cache size, so that people flush out of
it fairly quickly. That way, if someone starts ringing your site off
the hook, you can break the loop, but you don't lock them out of the
system for long if they ARE trying to get through.
--
Chuq Von Rospach - Plaidworks Consulting (mailto:[EMAIL PROTECTED])
Apple Mail List Gnome (mailto:[EMAIL PROTECTED])
And they sit at the bar and put bread in my jar
and say 'Man, what are you doing here?'"
