Hello, postfix.
I have many virtual domains, stored in MySQL database. To reject
some spam I check all HELOs not to be any of my domain (because it is
fake HELOs for sure). I have such check written like this:
smtpd_helo_restrictions = permit_mynetworks,
permit_sasl_authenticated,
reject_invalid_helo_hostname,
reject_non_fqdn_helo_hostname,
reject_unknown_helo_hostname,
check_helo_access
mysql:$config_directory/virtual_all_domains.cf,
permit
virtual_all_domains.cf contains this SQL statement:
query = SELECT "550 Invalid HELO: it is me!" FROM domain WHERE name = '%s' AND
active;
Ok. It works. For example, here is 'serebryakov.spb.ru' domain in
database, and it is active. Postfix rejects mail from such HELO:
==================================================================================
> telnet mail.serebryakov.spb.ru 25
Trying 195.131.4.140...
Connected to mail.serebryakov.spb.ru.
Escape character is '^]'.
220 ftp.translate.ru ESMTP Postfix (2.5.6)
EHLO serebryakov.spb.ru
250-ftp.translate.ru
250-PIPELINING
250-SIZE 10240000
250-ETRN
250-STARTTLS
250-AUTH DIGEST-MD5 CRAM-MD5 NTLM RPA
250-AUTH=DIGEST-MD5 CRAM-MD5 NTLM RPA
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
MAIL FROM: <b...@rejected.com>
250 2.1.0 Ok
RCPT TO: <l...@serebryakov.spb.ru>
550 5.7.1 <serebryakov.spb.ru>: Helo command rejected: Invalid HELO: it is me!
==================================================================================
Great. Works as expected.
BUT! It rejects mail from "gateway.home.serebryakov.spb.ru" TOO!
==================================================================================
> telnet mail.serebryakov.spb.ru 25
Trying 195.131.4.140...
Connected to mail.serebryakov.spb.ru.
Escape character is '^]'.
220 ftp.translate.ru ESMTP Postfix (2.5.6)
EHLO gateway.home.serebryakov.spb.ru
250-ftp.translate.ru
250-PIPELINING
250-SIZE 10240000
250-ETRN
250-STARTTLS
250-AUTH DIGEST-MD5 CRAM-MD5 NTLM RPA
250-AUTH=DIGEST-MD5 CRAM-MD5 NTLM RPA
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
MAIL FROM: <b...@rejected.com>
250 2.1.0 Ok
RCPT TO: <l...@serebryakov.spb.ru>
550 5.7.1 <gateway.home.serebryakov.spb.ru>: Helo command rejected: Invalid
HELO: it is me!
==================================================================================
BUT WHY!? Of course, SQL statement with this parameter doesn't
return ANY result!
--
// Black Lion AKA Lev Serebryakov <l...@serebryakov.spb.ru>
