On 8/4/2013 10:13 PM, Ronald F. Guilmette wrote:
> In message <[email protected]>, 
> Noel Jones <[email protected]> wrote:
> 
>> On 8/4/2013 8:06 PM, Ronald F. Guilmette wrote:
>>> Does reject_non_fqdn_helo_hostname, when placed in the
>>> smtpd_helo_restrictions, permit clients to HELO/EHLO
>>> with a square-bracket enclosed dotted quad IPv4 address?
>>
>> Yes.
> 
> The documentatation should probably be adjusted to make that more clear.
> Right now it reads:
> 
>      Reject the request when the HELO or EHLO hostname is not in fully-
>      qualified domain form, as required by the RFC. 
> 
>>> If so, is the dotted quad checked to see that it properly
>>> represents the actual IP address of the actual current client?
>>
>> No.
> 
> Is there any restriction verb that would cause a HELO/EHLO which specifies
> a square-bracketed dotted quad IPv4 address to be rejected when & if the
> dotted quad does not match the actual current client IP address?

I use a pcre table to reject any HELO that starts with a bracket or
looks like an IP. Legit hosts that use this form are very rare here
-- maybe one every couple years.

> 
> Would reject_unknown_helo_hostname do it?  If not maybe a new restriction
> verb would be useful to perform this exact check.

There is  no built-in postfix restriction to compare the HELO to the
client hostname, and I would question the value of such a feature.

Do you see lots of spam with incorrect IP in the HELO? Do you see
significant numbers of legit hosts using a bracketed IP HELO?


> 
>>> Certainly, some spam
>>> that I believe should have been rejected on the basis of one or another
>>> of the above RHS filters I am instead seeing (in my maillog file) being
>>> rejected instead by one or another of the subsequent reject_rbl_client
>>> filters.   What could I be doing wrong?
>>

You'll need too show evidence for further help on this.


>>
>> Doing RBL client checks in postscreen?
> 
> I am not using postscreen at the present time.
> 
> Do I need to use that if I want to perform RHSBL checks?

RHSBL checks work without postscreen.  If you use postscreen, it
will reject clients before the smtpd_*_restrictions (and the smtpd
program itself) are ever run.

http://www.postfix.org/POSTSCREEN_README.html


  -- Noel Jones

> 
> 
> Regards,
> rfg
> 

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