Yes, mess is a Scrabble word!
...and is worth 6 points in Scrabble, and 7 points in Words with Friends
mess
Verb
1. Eat in a mess hall
2. Make a mess of or create disorder in
Noun
1. A state of confusion and disorderliness
2. Informal terms for a difficult situation
3. Soft semiliquid food
4. A meal eaten in a mess hall by service personnel
5. A (large) military dining room where service personnel eat or relax
6. (often followed by `of') a large number or amount or extent
What Scrabble words can I make with the letters in mess?
3 Letter Words
2 Letter Words