[jzieger2]

I think people do these things mainly to deal with inadvertent disclosure (e.g., an incorrectly addressed email) or further downstream distribution of an email. The idea is to have some indicator that the original sender meant the communication to remain in confidence (which may be required to maintain, for example, attorney client privilege, or to preserve trade secret protection). When they are affixed automatically to every email (as they are by many firms), I really doubt they work. I'm not aware of any case where the existence of this kind of disclaimer has been a factor, and I suspect most people put this in the "it couldn't hurt" category, rather than really thinking it'll be effective. Would be interested to hear if anyone is aware of evidence to the contrary.

[yajoe]

They are effectively worthless if it can be shown they are added automatically to every mail. Privileged communication requires something explicit or genuine intent, i.e. the sender writing 'privileged' at the top. It actually can be quite bad if it's shown that the privileged communication was abused (either in terms of piercing all veils or censure).

My experience is people add these signatures because they see other people doing it and they assume it's a good practice or seemingly professional. It may be some inexperienced lawyers recommend it so they have something to say about email policy. It's not hurting anyone beyond eating up mail quotas, right?

[rsingel]

Hey John, that's pretty much what I found when I did an explainer for Wired about them:

“You have no obligation to obey the disclaimer if you decide to read a misdirected email, send it to your friends, or send it to a Wired reporter,” says Susan Lyon, a privacy and data security attorney for Perkins Coie. “You don’t have to worry about that.”

http://www.wired.com/magazine/2010/12/pr_burningquestion_leg...