> e.g. spammers are fond of using forged email addresses, e.g. > "[EMAIL PROTECTED]" etc. which change for every spam sent. > Traditionally this is hard to block. However Postfix will query > Hotmail.com as to whether such an account really exists. If it does not -- > the mail is rejected.
Hows postfix going to know for sure if the account really exists, a lot of the mail exchangers just accept mail bound for a domain....most of em dont even reveal wether a mail is valid or not (which if enabled, is a good way to harvest addresses)? for example, Trying 65.54.252.99... Connected to mc5.law1.hotmail.com (65.54.252.99). Escape character is '^]'. 220 mc5-f29.law1.hotmail.com Microsoft ESMTP MAIL Service, Version: 5.0.2195.5600 ready at Wed, 26 Mar 2003 07:56:08 -0800 vrfy hotchick12345 252 Cannot VRFY user, but will take message for <[EMAIL PROTECTED]> telnet darna.madugas.org smtp Trying 207.245.115.20... Connected to adsl-207-245-115-20.cust.oldcity.dca.net (207.245.115.20). Escape character is '^]'. 220 darna.madugas.org ESMTP Sendmail 8.11.6/8.11.6; Wed, 26 Mar 2003 12:05:48 -0500 vrfy lsdfjadlsjfsf 252 2.5.2 Cannot VRFY user; try RCPT to attempt delivery (or try finger) vrfy mister 252 2.5.2 Cannot VRFY user; try RCPT to attempt delivery (or try finger) jondz _ Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph To leave: send "unsubscribe" in the body to [EMAIL PROTECTED] Fully Searchable Archives With Friendly Web Interface at http://marc.free.net.ph To subscribe to the Linux Newbies' List: send "subscribe" in the body to [EMAIL PROTECTED]
