I just started a batch of mead using one of Jack Keller's recipes. As
the recipe (Vanilla Mead) did not specify any type of Sulfite I
checked the rest of Jack's recipes and noticed that none of them
specified any sulfite.

My question is should I use sulfite during fermentation? And, should I
use sulfite during ageing and bottling?

I suspect that, as Jack did not specify sulfite in the mead recipe it
is not necessary but what makes mead different from other wines made
from fruit? Is it something in the honey?