[Dshield] little experiment

Abuse abuse at what4now.com
Thu Mar 3 01:18:49 GMT 2005

** Reply to message from Henry Hertz Hobbit <hhhobbit at comcast.net> on Wed, 02
Mar 2005 11:28:52 -0700

> I am not using nis, nisplus, or db on this machine.  So if you were
> counting on this tip to work, it is some sort of anomaly that only works
> with Windows.  I am trying to think if there is some reason it needs to
> be there from the transport layer network perspective, and don't have an
> answer right now.  By that I mean, if you have multiple machines on an
> internal NAT'd subnet all talking to the same external SMTP server, is
> it needed to avoid collisions?  I would say no, since each connection IS
> a dedicated TCP connection.  For some reason there is this nagging
> thought in the back of my mind that the sending IP is required by some
> RFC for email.

RFC2821 says
"received from" domain name or IP address (from HELO) followed by "(" tcp-info
tcp-info = IP address of connection and domain name from DNS of IP address of
the connection

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