--On 9 February 2007 01:38:22 +0100 Magnus Holmgren
<holmgren@???> wrote:
> On Friday 09 February 2007 01:10, Tiago T. Adloff wrote:
>> I wanna know if there is some kind of filter in exim or addon, that can
>> blocks a sending when the limit of "to" and/or "cc" addresses exceed a
>> certain number predetermined.
>>
>> With this I can stop spammers clients using my MTA.
>
> Stop spammers from spamming you, or stop your users from spamming others?
> You aren't letting spammers use your server as an open relay, are you?
>
> You might be interested in the ratelimit ACL condition:
>
> http://www.exim.org/exim-html-4.66/doc/html/spec_html/ch40.html#SECTratel
> imiting
>
> If you want to limit the number of recipients per mail or the number of
> mails per connection, there are simpler ways.
search for "rcpt_count" in the docs
<
http://www.exim.org/exim-pdf-4.66/doc/spec.pdf>, and understand that an
email without either To: or Cc: headers can have thousands of Bcc
recipients. Alternatively, an email with thousands of addresses in the To:
header might actually have only one recipient. See
<
https://helpdesk.islandnet.com/pep/smtp.php>, for example.
> I don't suppose you mean
> that you want to limit the number of apparent recipients in the To: and
> Cc: header fields. :-)
He might do. That's something I'm trying to implement here, after a very
nasty internal spam attack. Someone emailed all students on campus, and
included 20,000 email addresses in the To: header. 70 people hit
reply-to-all.
What I'm trying to do, if I can get the syntax right, is replace long
headers To: and Cc: headers (say, more than 1024 chars) with a comment like
"long list hidden by postmaster:;". I don't see a way of actually counting
the number of addresses, which I'd slightly prefer.
--
Ian Eiloart
IT Services, University of Sussex
