[CentOS] pop3 attack

Bill Campbell centos at celestial.com
Fri Mar 13 19:21:54 UTC 2009


On Fri, Mar 13, 2009, William L. Maltby wrote:
>
>On Fri, 2009-03-13 at 14:51 -0400, James Pifer wrote:
>> > The masquerading options are for a different purpose.
>> > I'm glad you got it sorted out.
>> 
>> 
>> Although I'm able to send mail to most people without a problem using
>> smarthost, I still have a few that bounce back with errors like:
>> Your message was rejected by mail.lance.com for the following reason:
>> 
>>      Service unavailable; Client host [cdptpa-omtalb.mail.rr.com] blocked by zen.spamhaus.org; http://www.spamhaus.org/query/bl?ip=70.62.90.185
>> 
>> I'm using the smarthost server that I should be using according to the information:
>> define(`SMART_HOST',`smtp-server.carolina.rr.com')dnl
>> 
>> Although I'm in a residential IP range, my connection is Business Class, so sending smtp mail is not restricted (at least contractually). 
>> 
>> Why would I still have this problem if I'm using smarthost? Is there a way to resolve it?
>
>I would contact the RR support folks. I think they are the ones that
>would need to clean up the blacklist entry with Spamhaus. They should
>also be able to help ensure that your configuration is right. Just be
>prepared to get through the level 1 support delays before you get any
>help though. That's been my experience.

Your IP address, 70.62.90.185 is in two DNSRBLs we check,
dul.dnsbl.sorbs.net and zen.spamhaus.org.  The sorbs listing is
of dynamic IP addresses, and zen is a conglomeration of several
of the spamhaus.net DNSRBLs.

Both of these DNSRBLs are widely used, thus it would be a good
idea to either get a static IP from Road Runner that's not listed
in either of these, or to use a smart-host for outgoing e-mail
that will accept mail from your server regardless of the DNSRBL
listings.

Bill
-- 
INTERNET:   bill at celestial.com  Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/  PO Box 820; 6641 E. Mercer Way
Voice:          (206) 236-1676  Mercer Island, WA 98040-0820
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DOS: n., A small annoying boot virus that causes random spontaneous system
     crashes, usually just before saving a massive project.  Easily cured by
     UNIX.  See also MS-DOS, IBM-DOS, DR-DOS.


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