Yes, it’s real. This is a common email /request to people who use trademarks in a domain name.
Notice that they are not asking you for money or making any legal claims against you. They are simply informing you of the law and asking you to stop using the trademark in the domain.
Easiest is to reply and say you were umaware of intellectual property laws and say you will not be using or renewing the domain.
They won’t pursue the issue any further.
I had a similar problem when I used “paypal” as part of some domains. I also had a second tld that did not get a notification. I just dropped them both no big deal.