5 letter words:
fixes15,
mixes14,
4 letter words:
fems9,
feis7,
seif7,
mise6,
semi6,
simi6,
3 letter words:
fix13,
mix12,
sex10,
six10,
xis10,
fem8,
efs6,
fes6,
fie6,
ifs6,
sif6,
ems5,
ism5,
mes5,
mis5,
sim5,
sei3,
2 letter words:
ex9,
xi9,
ef5,
fe5,
if5,
em4,
me4,
mi4,
es2,
is2,
si2,