Over the years, I have helped more than my fair share of legitimate companies fight bogus patent lawsuit. But this one does not fit the usual pattern of "greedy contingency law firm X found useful idiot Y to sue big company Z for infringement of generic, trivial patent P that should never have been granted and that Y's corporate counsel found lying in a drawer at tiny company T that they acquired a few years ago." There are variations of course; the most common one is where plaintiff Y has been engineered from scratch for purposes of the litigation and belongs to a corporate group of similar companies, none of which have products that have ever sold a single copy to a non-insider.

This lawsuit, in a way, is legitimate in that the plaintiff is a real company with real products and nonzero market share, suing a genuine competitor that is not Microsoft, IBM or one of the usual imaginary competitors that just so happen to have a lot of money. The patent, although trivial in my opinion with respect to SMTP, relates to the products they are selling and not to some imaginary product that you could not even purchase if you wanted to, because it only exists as a paper creation in a court filing. This does not look like the usual drawer creations whose only purpose is to permit frivolous lawsuits. It looks like the kind of patent that some companies file defensively, to prevent someone else from filing and suing them. I can readily imagine that this was the plan in 1997 when the patent was filed. I invented double opt-in in 1993 and maybe I should have filed a defensive patent. Someone else did in 1998 and a few acquisitions later, Return Path now own that patent, so technically they could sue me for my own invention. I doubt Matt would ever do that and, if he did, I doubt he would win, but many companies file patents to avoid having to worry about this.

This of course does not excuse or even explain the use of a trivial defensive patent to try and sue a competitor out of the marketplace. This being said, when helping a company defend a patent case, I have found that it is important to remain as neutral as possible whenever there is a doubt, because otherwise you cannot give them the best advice. Bearing that in mind, at this point, I note that I do not know what Barracuda did or who started the fight.

I think the patent is trivial with respect to SMTP because "SMTP proxy" is a misnomer, a fancy word for a concept that is inherent to the 1982 SMTP standard. SMTP servers receive mail and either bounce it or pass it along to either a downstream SMTP server, a local mailbox, or anything under the sun (database, script, automatic translator, you name it). Every SMTP server performs this basic function, one way or the other. An SMTP server that does not either deliver or bounce messages would be theoretically possible, but in practice useless for mail delivery.

Every reasonable SMTP server is going to have a function that decides whether to keep or bounce incoming mail, and such has been the case since 1982. Given the existence of this function, I think it is a trivial "discovery" that you can insert code to look for harmful content and reject it. To wit, profanity filters have existed since even before my time (1985). If you accept that looking for and rejecting profanity is a trivial evolution of the SMTP concept, surely the same can be said about computer viruses.

Based on my cursory layman's review of the patent, I do not currently think that LISTSERV constitutes prior art, because the patent very specifically refers to virus scanning, which was not built in to LISTSERV at the time the patent was filed, and to the SMTP proxy function, which has never been part of LISTSERV. As for FTP, LISTSERV does not use it at all. Sorry I couldn't help this time.

  Eric