"Peter J. Holzer" <[EMAIL PROTECTED]> wrote: PJH> There's a good chance you have configured 127.0.0.1 as relayclient, in PJH> which case that check would actually return that the address exists.
Peter, are you suggesting that setting up 127.0.0.1 as a relay client is a bad idea, if yes, then how do we allow local server scripts/programs to send email? -- Best regards, Ashish mailto:[EMAIL PROTECTED] Children are unpredictable. You never know what inconsistency they're going to catch you in next. Franklin P. Jones ********************************************************************* Internet Wizards - The finest in web services! http://www.inwiz.com ********************************************************************* Sunday, December 21, 2003, 9:41:32 PM, you wrote: PJH> On 2003-12-21 10:34:17 -0500, Guillaume Filion wrote: >> Le 03-12-21, � 08:43, John Peacock a �crit : >> >Peter J. Holzer wrote: >> >>Suppose a spammer registers a domain spammers-r.us, adds these DNS >> >>records: >> >>spammers-r.us MX 10 mail.spammers-r.us >> >>mail.spammers-r.us A 127.0.0.1 >> > >> >This is exactly what I have already seen at least once with a >> >mainsleaze spammer. I can't find my notes, so I cannot confirm this, >> >but I do remember that it caused my MTA issues (basically mailbombed >> >itself trying to bounce a message). >> > >> >It would be wise to try and program with this evil behavior in mind... >> >> I agree, but there would be a lot of subnets to include, because >> spammers could use localhost (120.0.0.0/8), private addresses PJH> 127 >> (10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12) PJH> Yes. Plus the link-local net (169.254.0.0/16) and multicast addresses PJH> (224.0.0.0/4). These are guaranteed not to be reachable over the public PJH> internet. >> and any of the IANA reserved subnets (a lot! >> http://www.iana.org/assignments/ipv4-address-space) PJH> Only if you are prepared to track any changes in the list. I'd expect to PJH> hand out IANA these reserved subnets over time. >> It might be simpler to make an SMTP connection to the MX RR of the >> sender's domain, and maibe even do a MAIL FROM: <>, RCPT TO: >> $senderAddress to do a simple address check. PJH> There's a good chance you have configured 127.0.0.1 as relayclient, in PJH> which case that check would actually return that the address exists. PJH> hp
