hi!

>> mailx.courier-mta.com[216.254.115.190] just told me that:
>>> 517 HELO someservername2.domain.de does not match 
>>> ::ffff:123.123.12.12 (in reply to MAIL FROM command)
>> actually the dns-entry for that address is
>> someservername2-1.domain.de
> 
> No. The Host someservername2.domain.de does not even exist.

these were of course just examples. check the headers of this very
message and you will see:

smtp2-1.tng.de ([213.178.66.95] helo=smtp2.tng.de

host output:

smtp2-1.tng.de has address 213.178.66.95
95.66.178.213.in-addr.arpa domain name pointer smtp2-1.tng.de.
smtp2.tng.de has address 213.178.64.96
smtp2.tng.de has address 213.178.64.95
Host 96.64.178.213.in-addr.arpa not found: 3(NXDOMAIN)
Host 95.64.178.213.in-addr.arpa not found: 3(NXDOMAIN)

so they DO exist, it's just that DNS ans HELO name don't match.

> I think you messed something up in quoting the error because
> nonexisting host names should cause another error message.

nope. i just pasted the bounce message (and changed the hostnames and
the ip-address. useless idea, i know.)

> Two different things.
> 
> The thing mentioned in the FAQ is just for recording in the
> "Received" header field. The one causing your error is a
> spam-protection feature.

i don't see how this should prevent spammers from doing anything. spam
protection is a complicated thing and cannot be done by simple checkups.

>> i use my provider's smtp as smarthost and complained, but they told
>> me that this check SHOULD NOT be done according to the RFCs. (they
>> did not say which RFC they refer to.)

oh, and they said, their smtp-systems are a cluster, so DNS-lookup
*cannot* work all the time anyway. still sounds like they're right.

> I cannot see this "SHOULD NOT" in RFC 2821 or RFC 821. And I don't
> know of any other RFC that applies here.

from alessandro's message:

RFC2821:
> An SMTP server MAY verify that the domain name parameter in the EHLO 
> command actually corresponds to the IP address of the client. 
> However, the server MUST NOT refuse to accept a message for this 
> reason if the verification fails: the information about verification 
> failure is for logging and tracing only.

so, it is definitely a misconfiguration.

>> i guess they are right, otherwise they would have been flooded with
>>  complaints.
> 
> Oh, I think they should have been flooded with complaints. And, of
> course, they really should fix their setup.

i had never ever received a bounce like the one mentioned before that one.

if my provider had done such a stupid thing, thousands of mails would
bounce every day. they don't. except from mailx.courier-mta.org.

n.

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
courier-users mailing list
[email protected]
Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users

Reply via email to