Date: Fri, 16 Jan 1998 12:16:49 +0100 (MEZ) From: Robert Eckardt <roberte@mep.ruhr-uni-bochum.de> To: randyk@ccsales.com (Randy A. Katz) Cc: freebsd-questions@FreeBSD.ORG Subject: Re: sendmail - anti-spam, relay hosts Message-ID: <199801161116.MAA04054@beta.mep.ruhr-uni-bochum.de> In-Reply-To: <3.0.5.32.19980115222057.02ed7e50@ccsales.com> from "Randy A. Katz" at "Jan 15, 98 10:20:57 pm"
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> Hello,
>
> I know this is not for sendmail but I always get the best answers here and
> I'm using FreeBSD.
>
> I put in the rules to sendmail.cf for not allowing others to relay mail
> through our server. I have a number of virtual web sites on the server and
> each has a POP account and sends/receives email to/from the POP and to the
> world (the users are allowed to use us as their SMTP host).
>
> As soon as I put the no relay rules in they can no longer use us as an SMTP
> host. Is there a way to allow them if they are a valid POP account?
I have a similar problem:
I configured G as a relay for A.
I permit relaying for incoming mails only when the receiver is
in the local network(s) (check_rcpt).
As long as A runs everything works fine (no relaying needed).
But when A went down I suddenly saw rejected mail due to check_rcpt.
Changeing check_rcpt to display some debugging output (always in danger
that I get removed from "some" mailing lists for bouncing :-) I found
that the sender's address caused check_rcpt to complain.
I.e.: X.Y.Z --> A.M.R.de ==> No relaying on G.M.R.de
The domain is listed as M.R.de in /etc/sendmail.cR (in this example).
Why is check_rcpt called for the sender's address ?
The rule works fine for the recipient's address.
Robert
Besides: My check_rcpt at the very end of /etc/sendmail.cf looks like:
FR-o /etc/sendmail.cR
Scheck_rcpt
# anything terminating locally is ok
# R<$+ @ $* $=R > $#error $: "451 Relaying test " $1 " @ " $2 " " $3
R<$+ @ $=w > $@ OK
R<$+ @ $* $=R > $@ OK
# anything originating locally is ok
R$* $: $(dequote "" $&{client_name} $)
R$=w $@ OK
R$*$=R $@ OK
R$@ $@ OK
# anything else is bogus
R$* $#error $: "550 We do Not permit Relaying " $1
Kspammers hash /etc/sendmail.spammers
Scheck_mail
# check for valid domain name
R$* $: <?> $>3 $1
R<?> $* < @ $+ . > $: <OK>
R<?> $* < @ $+ > $#error $: "451 Domain/Host name must Resolve"
# check relay against spammers database
R$* $: $(spammers $&{client_name} $: OK $)
ROK $@ OK
R$+ $#error $: 551 $1
--
Dr. Robert Eckardt (
Ruhr-Universitaet Bochum, Inst.f.Theor.Physik, NB6/169 )
Universitaetsstrasse 150, D-44780 Bochum, Germany ----X---8----
Telefon: +49 234 700-3709, Telefax: +49 234 7094-574 8
E-Mail: RobertE@MEP.Ruhr-Uni-Bochum.de --------8----
URL: http://WWW.MEP.Ruhr-Uni-Bochum.de/~roberte
>>> A magician never reveals his secret: the unbelievable trick becomes <<<
>>> simple and obvious once it is explained. <<<
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