The letters in EXTREMELY make 88 words of two letters or more. The longest is EXTREMELY at 9 letters, and the highest-scoring is EXTREMELY at 21 points.
No other single word uses all 9 letters of EXTREMELY. EXTREMELY has 9 letters: 3 vowels and 6 consonants, worth 21 points before any board bonuses.
9-letter words 1
7-letter words 1
6-letter words 11
5-letter words 14
emeer7emery10exert12leery8melee7merle7meter7metre7relet5remet7remex14retem7telex12xylem17
4-letter words 26
eely7eery7elmy9eyer7eyre7leer4leet4lyre7meet6melt6mere6merl6mete6reel4rely7rete4teel4teem6tele4term6tree4trey7tyee7tyer7tyre7ylem9
3-letter words 24
eel3elm5eme5ere3ert3eye6lee3let3lex10ley6lye6mel5met5ree3rem5ret3rex10rye6tee3tel3try6tye6yer6yet6
2-letter words 11
el2em4er2et2ex9lm4lx9me4my7re2ye5
Words are from our open word list and include some game-only words. Rude words are left out of this page; the unscrambler shows every valid word, lets you add blank tiles and filter by length.