postfix/smtpd: warning: <ipaddr>: hostname <fqdn> verification failed

[Gunnar Wrobel]

Quoting Gavin McCullagh <gavin.mccullagh at gcd.ie>:

> Hi,
>
> on our v2.2.3 kolab install, we're getting regular messages like:
>
> Jul 16 10:48:45 XXXXX <warning> postfix/smtpd[23939]: warning:  
> 93.86.229.159: hostname 93-86-229-159.dynamic.isp.telekom.rs  
> verification failed: Name or service not known
> Jul 16 10:50:31 XXXXX <warning> postfix/smtpd[23939]: warning:  
> 59.164.0.50: hostname 59.164.0.50.man-dynamic.vsnl.net.in  
> verification failed: Name or service not known
> Jul 16 10:53:16 XXXXX <warning> postfix/smtpd[23941]: warning:  
> 77.75.100.210: hostname as100210.airspeed.ie verification failed:  
> Name or service not known
>
> As far as I can see, this is postfix warning of an incoming smtp
> connections from hosts who have a PTR record, but that PTR record doesn't
> have a corresponding A record.  Is that right?
>
> Does postfix reject that connection or does it just warn me of it?

I believe this is just a warning. Though you will certainly find a  
setting that allows you to reject such connections.

>
> Which entry in main.cf triggers this check?

That I don't know and I would have to check the postfix manual myself.

> Is this the kolab_smtpdpolicy
> stuff?

No. I believe "postfix/smtpd" indicates that these messages originate  
from the smtpd process. So when you look at the postfix configuration  
for this process you should be able to find the parameters influencing  
this check.

Cheers,

Gunnar

>
> Most of the warnings appear to be from hosts which look like they're in
> dynamic ISP allocations.  These probably are SPAM bots, so this behaviour
> seems reasonable.  I'd just like to understand it a little better.
>
> Thanks in advance,
> Gavin
>
>
> _______________________________________________
> Kolab-users mailing list
> Kolab-users at kolab.org
> https://kolab.org/mailman/listinfo/kolab-users
>



-- 
______ http://kdab.com _______________ http://kolab-konsortium.com _

p at rdus Kolab work is funded in part by KDAB and the Kolab Konsortium

____ http://www.pardus.de _________________ http://gunnarwrobel.de _
E-mail : p at rdus.de                                 Dr. Gunnar Wrobel
Tel.   : +49 700 6245 0000                          Bundesstrasse 29
Fax    : +49 721 1513 52322                          D-20146 Hamburg
--------------------------------------------------------------------
    >> Mail at ease - Rent a kolab groupware server at p at rdus <<
--------------------------------------------------------------------

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 197 bytes
Desc: Digitale PGP-Unterschrift
URL: <http://lists.kolab.org/pipermail/users/attachments/20100718/df725f7b/attachment.sig>