[AusNOG] [off-topic] Email disclaimers

[Kai]

Hi guys and girls,

Sorry for off-topic post, been meaning to ask about it for a while but never got around to it.

Email disclaimers, you know those messages included in email footers that are often bigger than the actual email body and say something like:

IMPORTANT NOTICE-This email and any attachments may be confidential. If you are not the intended recipient, you should not disclose or use the information contained in it. If you have received this email in error, please notify us immediately by return email, and delete the email and its attachments. <insert name here> is not responsible for any changes made to a document other than those made by <insert name here>

How valid are they? would they be usable in court if need be?

Cheers
Kai