Am 09.07.2010 16:13, schrieb Administrator Beckspaced.com: > > > On 7/9/2010 14:40, Ram wrote: >> On Fri, 2010-07-09 at 13:35 +0200, Administrator Beckspaced.com wrote: >>> On 7/9/2010 13:27, Robert Schetterer wrote: >>>> Am 09.07.2010 12:51, schrieb Administrator Beckspaced.com: >>>>> hello robert, >>>>> >>>>> thanks a lot for your quick reply ... >>>>> actually it is not always the same IP or host sending the error >>>>> bounces ... >>>>> the bounces are sent from hundred of different IP addresses ... >>>>> >>>>> any more idea? >>>>> >> Usually you can do very little to prevent forging your domain and >> sending spam. >> Some months ago one client of ours too had the same issue, but the issue >> is very temporary. >> The short term solution , as someone suggested, will be to temporarily >> defer all NDR's with a sender check regex file like >> /<>/ 450 Try Later >> >> >> ( The RFC's say you cant do this .. but sometimes you must be >> practical :-) ) >> >> >> >> >> > From my personal experience I found that if , for your regular mailing >> you use some sender authentication mechanism like SPF then these NDR's >> significantly reduce. For eg many servers reject forged messages based >> on SPF checks so you dont get NDR's from them at least. >> >> I guess , spammers ( the more intelligent ones ... I mean ) too would >> be less inclined to forge a domain that uses sender authentication >> Because that will reduce the deliverability of their spams >> >> Thanks >> Ram >> >> >> >> >> > hello again robert & ram > > thanks again for your ideas ... > > so i had another search in google about that backscatter topic and sort > of found a nice, simple & also quick solution? > > SAFE MODE with Postfix: > > Edit /etc/postfix/main.cf: > smtpd_recipient_restrictions = > ... > check_sender_access dbm:/etc/postfix/check_backscatterer > ... > Create new file:/etc/postfix/check_backscatterer: > <> reject_rbl_client ips.backscatterer.org > postmaster reject_rbl_client ips.backscatterer.org > > well ... had to change the postfix dbm lookup to hash and do a postmap > on the file ... > but now this seems to work as it already rejected a few emails according > to the mail log ... > > more info can be found here -> > > http://www.backscatterer.org > > does anyone have any experience with that list? > is this a good longterm solution? > > best regards > becki >
in your case it may be a short/quick/easy solution but dont use this rbl on long time it has nearly every big mailhost in it you will loose legitime bounces you may additional only use this rbl for your backscatterered reciept and not for your whole server -- Best Regards MfG Robert Schetterer Germany/Munich/Bavaria
