In “My Account” > “Company” you MUST enter a physical address that will appear in the footer of Broadcasts and Autoresponses. That will be the default, which can be overridden in individual Lists to make them Client/Niche/Product specific.
By law in most Countries, there has to be a physical address, which can be an official PO. Box if you choose. It must however be one from which you would receive any snail mail sent to it.
It has become customery to add a disclaimer at the foot of emails – never a Can-Spam requirement, but one that people tend to confuse with it. This quote from The Economist shows their actual value:-
“Legal experts say that no court case has ever been determined by the absence (or appearance) of an email footer in the U.S.”
The Economist goes on to elaborate: “Many disclaimers are, in effect, seeking to impose a contractual obligation unilaterally, and thus are unenforceable. This is made totally clear in Europe, where a directive from the European Commission tells the courts to strike out any unreasonable contractual obligation on a consumer if he has not freely negotiated it.”
Effectively, such disclaimers are therefore worthless, and merely add a potential negative to what should be a totally positive communication.
You should however ensure that the following statement IS included as the last sentence of the footer, whether it be the only content, or not. “Should you wish to not receive these communications in future you may do so by using the “Unsubscribe” link below.”