David F. Skoll wrote:
On Wed, 5 Mar 2003, Clifton Royston wrote:
People might want to look at the recently-implemented Postfix
sender verification feature in current snapshot releases.
This technique is patented and assigned to ESCOM Corporation, in US
Patent #6,321,267 (see the section "Active User Testing")
The patent was filed 23 November 1999; if you think you have prior
art, I encourage you to publish it.
I don't think this patent is particularly relevent.
I've attached claim 1 below. In patents claim 1 is the most general of
all the claims.
In order to violate this patent you must have all three of the described
filters (and I suspect,
given the phrasing, exactly these three and no more).
More normal language would refer to 'a plurality of filters including
but not limited to
the following'.
So if you just leave out the dial up reverse connection detection (which
probably isn't
relevent any more in any case) you aren't violating this patent IMO.
- Rod
1. A system for detecting and selectively preventing reception of an
electronic message to a local message transfer agent (MTA), the
electronic message having an address identifying a sender and
transferred over a connection from a remote host, the system comprising:
a dialup filter determining whether the connection is a dialup
connection and, if the connection is a dialup connection, terminating
the connection;
a relay filter determining whether the remote host is an open relay and,
if the remote host is an open relay, terminating the connection; and,
a user filter verifying whether the sender of the electronic message is
authorized and, if the sender of the electronic message is not
authorized, terminating the connection;
wherein, said system establishes communication over the connection
between said remote host and the local MTA if said system determines
that the connection is not a dialup connection, said relay filter
determines that the remote host is not an open relay and said user
filter verifies the sender as authorized.
_______________________________________________
Asrg mailing list
Asrg(_at_)ietf(_dot_)org
https://www1.ietf.org/mailman/listinfo/asrg