Thanks Noel for all your help. Glad to know you.

--
Klaus Engelmann
CCNA CCDA - CSCO10971632
LPIC-1 - LPI000138061



On Wed, Apr 7, 2010 at 10:04 AM, Noel Jones <njo...@megan.vbhcs.org> wrote:
> On 4/6/2010 6:09 PM, Klaus Engelmann wrote:
>>
>> Hello Everybody.
>>
>> I am running a Postfix postfix-2.3.3-2.1.el5_2 on a CentOS 5.4 box at
>> a Federal University in Brazil.
>> Our users (students and professors) suffered several social
>> engineering attacks and spammers got some valid users and passwords.
>>
>> I know that the spammers are using a fake email (i...@freelotto.com)
>> to send SPAM through our MX. But they are using some unidentified
>> usernames.
>>
>> I need some help or thoughts about:
>>
>> - which parameter at master.cf or main.cf can I turn on in order to
>> see the IP used by a specif user (authentication against SASL DOVECOT)
>> or
>> to see the IP address used by the sender i...@freelotto.com.
>
> The logs already show all this information.
>
> When someone authenticates with sasl, there will be a line including
> client=name[IP], sasl_method=FOO, and sasl_username=tito.  Searching the log
> for "sasl_username=tito" will show each time user tito authenticated, and
> from which IP.
>
> To find the IP a sender address comes from, search the log for the sender
> you're interested in, then search again for the QUEUEID associated with that
> sender.
>
> Truncated Example:
> # grep 'njo...@example.com' /var/log/maillog
> postfix/qmgr[95868]: 39B95797897: from=<njo...@example.com>, size=2619,
> nrcpt=1 (queue active)
>
>
> # grep 39B95797897 /var/log/maillog
> postfix/smtpd[16982]: 39B95797897:
> client=client-192.1.0.34.example.net[192.1.0.34]
> (and other lines associated with this QUEUEID)
>
> You can also record this information in the Received: header of the mail.
> http://www.postfix.org/postconf.5.html#smtpd_sasl_authenticated_header
>
>  -- Noel Jones
>

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