R: R: [OT] How to avoid Backscatter in Sendmail

[Marcello Anderlini]

Thanks you for your time and help but  the ip wich has problem is
83.216.185.66.
I configured my access file but instead to refuse the email at smtp
connection the system still sends an email of NDR. 


Dr. Marcello Anderlini
m.anderlini at database.it
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Database Informatica S.r.l.
Microsoft Certified Partner
Tel.  +39059775070
Fax. +39059779545
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-----Messaggio originale-----
Da: mailscanner-bounces at lists.mailscanner.info
[mailto:mailscanner-bounces at lists.mailscanner.info] Per conto di Steve
Freegard
Inviato: 21/04/2010 16:08
A: MailScanner discussion
Oggetto: Re: R: [OT] How to avoid Backscatter in Sendmail

On 21/04/10 14:50, Marcello Anderlini wrote:
> No my system is a Linux Centos with sendmail

If the mailboxes are for local UNIX users then generating backscatter for
unknown users is impossible unless you are using something like Cyrus (which
requires a plug-in to verify users).

I've just checked and unless I'm missing something:

smf at smf-laptop:~$ host -t MX database.it database.it mail is handled by 10
netra2.database.it.

smf at smf-laptop:~$ host netra2.database.it netra2.database.it has address
83.216.185.70

smf at smf-laptop:~$ host 70.185.216.83.ips.backscatterer.org
Host 70.185.216.83.ips.backscatterer.org not found: 3(NXDOMAIN)

^^^ Shows that you are not listed

Also I checked:

smf at smf-laptop:~$ telnet netra2.database.it 25 Trying 83.216.185.70...
Connected to netra2.database.it (83.216.185.70).
Escape character is '^]'.
220 netra.database.it ESMTP Sendmail 8.13.1/8.13.1; Wed, 21 Apr 2010
16:07:36 +0200
EHLO foo
250-netra.database.it Hello
74-93-209-150-WashingtonDC.hfc.comcastbusiness.net [74.93.209.150], pleased
to meet you 250-ENHANCEDSTATUSCODES 250-PIPELINING 250-8BITMIME 250-SIZE
250-DSN 250-AUTH DIGEST-MD5 CRAM-MD5 LOGIN PLAIN 250-DELIVERBY 250 HELP MAIL
FROM:<> 250 2.1.0 <>... Sender ok RCPT TO:<sldjfskldjfslkdfjs at database.it>
550 5.1.1 <sldjfskldjfslkdfjs at database.it>... User unknown QUIT
221 2.0.0 netra.database.it closing connection Connection closed by foreign
host.

^^^ Shows that you are correctly rejecting unknown users at the SMTP stage.

So I can't see any problems at all.

Regards,
Steve.
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Messaggio verificato dal servizio antivirus di Database Informatica