Solutions :

3-letter words (1 point): 37

DIE; DIM; DIT; DUX; EMO; ENE; IDS; ITS; LEI; LET; LEX; LIE; MEL; MEN; MET; MID; MIX; MIZ; MOE; MOI; MOL; NET; OIL; OLE; SUD; TEL; TEN; TEX; TID; TIE; TIX; TUT; TUX; UDS; UTE; UTS; ZIT.

4-letter words (1 point): 50

DIEL; DIET; DIME; DIOL; DITE; DITS; DITT; DUST; EMIT; EXIT; ILEX; IMID; ITEM; LENT; LETS; LIEN; LOID; LOME; MENE; MENT; METS; MIDI; MIDS; MIEN; MITE; MITT; MIXT; MOIL; MOIT; MOLE; NETS; NETT; NEXT; OMEN; OMIT; STEM; STEN; STIE; STIM; STUD; TEIL; TENE; TENT; TEXT; TIDS; TIME; TUTS; ZITE; ZITI; ZITS.

5-letter words (2 points): 24

DIENE; DIETS; EMITS; EXITS; IDIOM; IMIDS; LOIDS; MIDST; MIXEN; MIXTE; MOITS; NETTS; NEXTS; NEXUS; OLENT; OMITS; STEIL; STENT; STIME; TEIID; TELOI; TENET; TEXTS; TIMID.

6-letter words (3 points): 10

EXTENT; LOMENT; MELOID; MITTEN; NETTIE; STIMIE; STUDIO; TEIIDS; TELNET; TENETS.

7-letter word (7 points): 1

MELOIDS.