Ivan Ricotti a écrit :
> Hello Ralf,
>
> thanks for your reply!
>
> Ralf Hildebrandt wrote:
>> reject_rbl_client cbl.abuseat.org,
>> reject_rbl_client sbl.spamhaus.org,
>>
>> can be merged into:
>> reject_rbl_client zen.spanhaus.org
>>
>
> ok, thanks.
>
and put that before spamcops list.
also remove reject_unauth_pipelining. it's useless in
smtpd_recipient_restrictions. you can put it under
smtpd_data_restrictions. but it won't catch a lot of junk...
Here is a "better" ordering of your checks:
smtpd_recipient_restrictions =
reject_non_fqdn_sender,
reject_non_fqdn_recipient,
reject_unknown_sender_domain,
reject_unknown_recipient_domain,
permit_mynetworks,
reject_unauth_destination,
reject_rbl_client zen.spamhaus.org,
reject_rbl_client bl.spamcop.net,
reject_invalid_hostname,
now, depending on your setup, I would remove
reject_unknown_recipient_domain and reject_unknown_sender_domain.
>>> Now in my /var/log/mail.info I have a lot of lines like this:
>>>
>>> Mar 25 11:35:10 athene postfix/smtpd[24933]: NOQUEUE: reject: RCPT from
>>> unknown[92.101.112.32]: 554 5.7.1 Service unavailable; Client host
>>> [92.101.112.32] blocked using bl.spamcop.net; Blocked - see
>>> http://www.spamcop.net/bl.shtml?92.101.112.32;
>>> from=<janicetyson.4...@aol.com> to=<giova...@elabor.homelinux.org>
>>> proto=SMTP helo=<ip-032-112-101-92.pools.atnet.ru>
>>>
>>> Now I fear to be source of backscatter emails. Is that my case?
>> No.
>>
>
> Wow! That's a very good news!
> Could I ask you why? What I missed?
>
reject != bounce
- reject means that postfix says: I don't want you message. go away.
This is done while the smtp client ("the other side") is connected.
- bounce means: postfix says "ok. I accept your message. I'll take care
of it", then later for some reason, the message can't be delivered.
since postfix accepted the message, it needs to generate a bounce. and
the bounce will go to the original envelope sender. unfortunately, this
sender may have been forged. in which case, the bounce goes to an
innocent who never asked for it. this is backscatter.
