There are also ways to silently drop (or accept with routing to /dev/null) a session for a recipient that isn't in an external database (eg: LDAP) -- and while this breaks the RFC, people do it anyway.
Ever looked at a Hotmail spam message? There will be 50 recipients ..gbush@, hbush@, jbush@, kbush@, etc. the ones that bounce aren't real and get rejected. Those that don't come back get added as "valid" for the second round.
~Mike. Dave Korn wrote:
Mar.Shatz@xxxxxxxxxxxxxxxx wrote:whitehouse.gov MX 100 mailhub-wh2.whitehouse.gov noone@box:~$ noone@box:~$ telnet mailhub-wh2.whitehouse.gov 25 Trying 63.161.169.140... Connected to mailhub-wh2.whitehouse.gov. Escape character is '^]'. 220 whitehouse.gov ESMTP service at Sun, 12 Feb 2006 11:29:38 -0500 (EST) helo jojo 250 esgeop03.whitehouse.gov Hello [xxx.xxx.xxx.xxx], pleased to meet you mail from:bob@xxxxxxx 250 2.1.0 bob@xxxxxxxxxx Sender ok rcpt to:gbush@xxxxxxxxxxxxxx 550 5.1.1 gbush@xxxxxxxxxxxxxxxxx User unknown rcpt to:president@xxxxxxxxxxxxxx 250 2.1.5 president@xxxxxxxxxxxxxxxxx Recipient ok quit 221 2.0.0 esgeop03.whitehouse.gov closing connection Connection closed by foreign host. User enumeration at the whitehouseTell DHS at once! What would happen if Al-Qaeda could figure out that there was a president in the whitehouse?cheers, DaveK
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