This is a wheel which gets re-invented by domainers time and time again. Every now and then, someone comes up with the idea that there is some magic legal voodoo token which will ward off UDRP complaints.
Short answer - it's a waste of time.
Longer answer - UDRP panels have used this sort of thing to argue that the domain registrant was a cybersquatter, thus having the exact opposite effect from that intended.
This is like the dumb "legal notices" that are used in online prostitution advertising.... "By contacting me, you agree that you are not law enforcement, and that you are not soliciting prostitution." Yeah, right. The only thing that does is scream "This is a prostitution ad."
These things always remind me of how small children "hide" by putting their hands over their faces, thinking that if they can't see you, then you can't see them. It looks about as sophisticated as well.
So, let's say you follow the suggestion above, and put this in your emailed attempt to unilaterally impose some kind of binding condition on the other side, and say your communications:
"cannot be considered as binding agreement or be used as evidence in a judicial or administrative proceeding."
Okay, fine. Now they go and file a UDRP and include all the communications. What happens? Does lightning come down from the sky and strike them dead? No. There are no "UDRP Rules of Evidence". The same Panel which is going to decide whether to "consider" those communications is the same Panel which is going to rule on the case. It's not as if they are going to "unsee" the evidence, and it is not at all comparable to a court proceeding in which a judge decides whether the jury is going to see a piece of evidence or not.
If you have a name like, say, BudweiserBeers.tld, it's not going to make a smidgeon of difference to a panel whether or not you have some magic incantation in your emails or on your site.
Oh, incidentally, by reading this post, you hereby agree to pick me up some sandwiches and beer, and send over someone to give me a foot massage. That condition on this post is about as practically effective for your emails in the situation you are describing.
A much, much better approach is to build your defense into your reply in the first place. For example, you have the domain name MyCat.tld. You get an email asking about the name. You reply with a price, and then you find out that the inquirer was representing the Caterpillar equipment company and they file a UDRP.
You'd be much better off if your reply stated, upfront, "I think this is a great name for selling cat care products or other subjects having to do with cats..." and then go on to what you would want for it. By doing that, you've "built in" the defense to the UDRP and they aren't going to want to use your email as evidence. In fact, if they don't, then you get to point out that they left out the part where you were going on about why it's a valuable domain name.
You can see this sort of thing in action in this dispute:
In the present case, there had been correspondence between the parties before the Complaint was filed. The Complainant has relied on part of that correspondence – an offer for sale – to try and establish bad faith on the part of the Respondent. In this Panel’s view, that offer did not assist the Complainant because the disputed domain name has value independently of its significance as the Complainant’s trademark. That is, it has value because it is the name of a popular tourist destination and, as the Panel has found above, the Respondent did not register the disputed domain name in bad faith.
The Respondent points to a different part of that correspondence. On March 21, 2014, the Respondent (or its broker) sent an electronic message to the Complainant seeking to justify its position:
“I am sorry we were unable to come to agreement about this domain name. ‘Puket’ is a common spelling of a well-known resort island in Thailand, and the owner has used the domain name to advertise Thailand travel for a very long time. The owner does not believe use of the domain name as a common geographic indicator has anything to do with your claimed trademark, and looks forward to addressing your UDRP complaint if necessary.”
If you are concerned about your communications during a negotiation being used as evidence, then think about that for a moment. You are generating the evidence. You get to decide what is IN that evidence when you write it. Rather than engaging in a futile, pointless and ultimately counterproductive exercise to avoid the use of your communications as evidence, then what you should be doing is thinking about what you want that record to look like instead of how you intend to argue that the Panel shouldn't pay any attention to what's been put under their noses.
Finally, hurry up with those sandwiches.
