Spam gets in on false confidentiality claims

I received the following:

I deal with all of the online marketing for a selection of UK law firms working in a range of different practice areas. [Spammy solicitation where I'm supposed to publish their advertising omitted.] ...
This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. ... If you are not the intended recipient of this email, you must neither take any action based upon its contents, nor copy or show it to anyone.

Oh, must I not?