topic Re: sendmail 8.9.3 , stop third party relays in Operating System - Linux

sendmail 8.9.3 , stop third party relays

Mike_Ca Li — Thu, 28 Aug 2003 03:17:55 GMT

Hi:
I did a :
#telnet relay-test.mail-abuse.org
Passed the previous 7 test cases, but not the 8th case:

<<< 220 xyz.com Server ESMTP ready at Thu, 28 Aug 2003 00:01:52 -0400
>>> HELO cygnus.mail-abuse.org
<<< 250 xyz.com Hello cygnus.mail-abuse.org
:Relay test: #Test 8
>>> mail from:
<<< 250 Ok
>>> rcpt to:
<<< 250 Ok
>>> QUIT
Local flow control off
<<< 221 xyz.com Out
Tested host banner: 220 xyz.com Server ESMTP ready at Thu, 28 Aug 2003 00:00
System appeared to accept 1 relay attempts
Connection closed by foreign host.

Am using sendmail 8.9.3 and relay should have been turned off by default? What do I need to
change in sendmail.cf or which script to use to generate the sendmail.cf entries?
Thanks.

Re: sendmail 8.9.3 , stop third party relays

Stuart Browne — Thu, 28 Aug 2003 03:39:04 GMT

what platform/distribution of Linux are you using? Why are you still usign such an old version of Sendmail?

Re: sendmail 8.9.3 , stop third party relays

Steven E. Protter — Thu, 28 Aug 2003 09:47:47 GMT

You should upgrade sendmail.

I believe the access file was implemented in 8.9.3 though.

You can carefully define relay ip addresses in the file /etc/mail/access

with the following format.

192.168.0.40 RELAY

Thats tab delimited data there.

Then you need a script like the one I'm attaching to rebuild the hash databases and generate a new snedmail.cf file.

You could turn on promiscuous relay in sendmail.mc and use my script but that would pretty much turn you into a spam relay and your ISP will shut you down pretty fast, unless they're totally corrupt.

See script.

SEP

Re: sendmail 8.9.3 , stop third party relays

Mike_Ca Li — Thu, 28 Aug 2003 11:18:46 GMT

Using sendmail on HPUX 11i.
I used the access.db also which an entry:
192.168.1relay
How about if mail.xyz.com resolves to 192.168.1.5 ? so, the case
rcpt to: will get through.
Then the sendmail will relay mail. How to fix in sendmail.cf so that the format

and
<"nobody@mail-abuse.org"@mail.xyz.com>
are not accepted by sendmail?