Solutions :

3-letter words (1 point): 57

AIS; ALA; ALE; ALS; EFS; ELS; ERF; ERS; FEN; FER; FES; FEU; FEZ; FIE; FIN; FIR; IFS; IOS; IRE; ISO; LAS; LEA; LES; LEZ; NEF; NIE; NUS; OES; OSE; OUS; REF; REI; REN; REO; RES; REZ; RIF; RIN; SAI; SAL; SAZ; SEA; SEI; SEL; SEN; SER; SEZ; SOU; SRI; SUE; SUI; SUN; UNI; USE; ZAS; ZEA; ZEL.

4-letter words (1 point): 45

ALAE; ALAS; ALEF; ALES; ALSO; ELSE; EUOI; FEAL; FENI; FEUS; FIER; FINE; FIRE; FIRS; IRES; ISLE; LASE; LAZE; NEFS; NEIF; NERD; NIEF; NIES; NIFE; REFS; REIF; REIN; REOS; RIFE; RIFS; RINE; SALE; SEAL; SEIF; SEIR; SELS; SERF; SERS; SIAL; SLAE; SUER; USER; ZEAL; ZEIN; ZELS.

5-letter words (2 points): 37

AISLE; ALEFS; DRIES; FEALS; FEAZE; FEZES; FIERS; FINER; FINES; FIRES; FRIES; ISLES; LASER; LAZES; LEAZE; LEZES; NEIFS; NERDS; NIEFS; NIFES; REFEL; REIFS; RINES; SALES; SAZES; SEALS; SEAZE; SEFER; SEIFS; SEIRS; SERFS; SERIF; SERIN; SLAES; SUERS; USERS; ZEALS.

6-letter words (3 points): 12

AISLES; ERINUS; FEAZES; FINERS; FRIEZE; LASERS; LEAZES; REFELS; RESALE; SEAZES; SERIFS; SLEAZE.

7-letter words (7 points): 2

FRIEZES; RESALES.