Re: [Exim] Blocking mail from "frozen" addresses

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Autor: Dave C.
Data:  
A: I. Forbes
CC: exim-users
Assumpte: Re: [Exim] Blocking mail from "frozen" addresses
Ah yes, but you were talking about frozen messages, which I presume to
mean that the _recipient_ is also invalid? If you set receiver_verify,
then exim can check the recipient at SMTP time, and refuse to accept the
message entirely..


On Wed, 21 Nov 2001, I. Forbes wrote:

> Hello Dave
>
> "sender_verify" will block mail from senders with bad domains, but
> it does not catch "spamer123@???" as hotmail.com is a
> valid domain.
>
> "sender_verify_hosts_callback" will block that mail, but it is
> "expensive" in terms of bandwidth and server load and is subject to
> temporary failures due to DNS availability. Using it may well slow
> down all incomming mail.
>
> The list of frozen messages provides a verified list of "bad" sender
> addresses, at no additional cost. Using them in a block list will not
> effect any valid incomming mail.
>
> I was just wondering whether anybody has done it before, and if not,
> am I missing something obvious?
>
> Thanks
>
> Ian
>
>
>
> On 20 Nov 2001, at 11:56, Dave C. wrote:
>
> >
> > You'll want to look into the receiver_verify and sender_verify options,
> > which should help prevent such mail from entering your system to begin
> > with
> >
> > On Tue, 20 Nov 2001, I. Forbes wrote:
> >
> > > Hello All
> > >
> > > We always seem to have a collection of frozen messages sitting on
> > > our mail queue with return addresses like
> > > "spammer123@???" (or others that would not get through
> > > a decency filter ...). Our setup keeps these on the queue for a few
> > > days and then deletes them. Often there are multiple messages
> > > from the same address. Obviously for every message that gets
> > > stuck, there are many more that get through to clog up our users
> > > mailboxes.
> > >
> > > I was wondering is it possible to setup something that scans the
> > > mail queue periodically and adds the return addresses of any
> > > frozen messages to a "sender_reject" list. Obviously this could be
> > > done independently of exim, with the aid of a python or perl script.
> > >
> > > - Has anybody tried anything like this?
> > >
> > > -   Is this a function which could/should be incorporated into exim
> > >     itself?

> > >
> > > If a sender is trying to send e-mail and his return address is invalid,
> > > as demonstrated by frozen bounce messages addressed to that
> > > address, surely it is a valid response to deny further mail from that
> > > sender.
> > >
> > > Any comments?
> > >
> > >
> > > Ian
> > >
> > > ---------------------------------------------------------------------
> > > Ian Forbes ZSD
> > > http://www.zsd.co.za
> > > Office: +27 21 683-1388 Fax: +27 21 674-1106
> > > Snail Mail: P.O. Box 46827, Glosderry, 7702, South Africa
> > > ---------------------------------------------------------------------
> > >
> > > --
> > >
> > > ## List details at http://www.exim.org/mailman/listinfo/exim-users Exim details at http://www.e
> xim.org/ ##
> > >
> > >
> >
> > --
> >
> >
> >
>
>
> ---------------------------------------------------------------------
> Ian Forbes ZSD
> http://www.zsd.co.za
> Office: +27 21 683-1388 Fax: +27 21 674-1106
> Snail Mail: P.O. Box 46827, Glosderry, 7702, South Africa
> ---------------------------------------------------------------------
>


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