this is how it worked for us - doesn't mean that is the case for you..
We got a dime a dozen of such communications from schools/coaches. Try to find a way that determines if it is legit or not. When it was a school that my son was really interested in - he would follow-up with an email to them/asking where they had seen him...or something that would require a reply. If they replied with a personal note (and in many cases they would cite a specific game/play) we knew it was legit/perhaps a lukewarm interest/on the list, etc.
However our rule of thumb was when a school was REALLY interested - there was a phone call with a coach. (typically they would ask our travel coach to have son call them at X time, etc.) These we considered hot leads.
In our mind we were only being recruited when there was an actual conversation.
But again...everyone is different. Good luck