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A good example of heavily broken SMTP client


I do not check HELO neither syntaxically nor for A RR now, just 
because too many of our business correspondent's corporate mailhosts 
use WinNT with broken HELO. In other case, this message could be 
blocked easily without MAPS RSS assistance: either by non-reversed IP 
or by strange HELO. And we can understand that the reasons of last 
two misconfigurations (HELO and open relay) is exactly the same: 
broken //root/dev/hands. Reverse IP is more complex problem, but 
(seems) normally anybody may and can use provider's smarthost for 
outbound mail until reverse zone delegation.

However, now I have realized that it is possible to implement formal 
HELO check in Zmailer using regexps in smtpserver.conf. Actual HELO- 
to-A-RR check and reverse DNS... seems, it requires new features. 

Other idea: applying regexps to reverse DNS result can filter many 
dialups which are not announced in MAPS DUL. *dialup*, *ppp*, etc.


------- Forwarded message follows -------
Date sent:      	Fri, 15 Jun 2001 00:12:43 +0400 (MSD)
From:           	MAILER-DAEMON@office.cpr.spb.ru (Mail Delivery System)
To:             	postmaster@cpr.spb.ru (Postmaster)
Subject:        	Postfix SMTP server: errors from unknown[]

Transcript of session follows.

 Out: 220 office.cpr.spb.ru ESMTP Postfix
 Out: 250-office.cpr.spb.ru
 Out: 250-SIZE 3000000
 Out: 250-ETRN
 Out: 250-STARTTLS
 Out: 250 8BITMIME
 In:  MAIL FROM:<*censored-by-aal*@pisem.net> SIZE=2381
 Out: 250 Ok
 In:  RCPT TO:<*censored-by-aal*@cpr.spb.ru>
 Out: 550 Service unavailable; [] blocked using
 In:  QUIT
 Out: 221 Bye

No message was collected successfully.

------- End of forwarded message -------

Alexey A. Lobanov AL258-RIPE
Clinical Pharmacological Research Institute, Head IT dept.
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