De or het mailbestand?

The correct Dutch article is:

de mailbestand

How to use mailbestand

the mailbestandde mailbestand
this mailbestanddeze mailbestand
that mailbestanddie mailbestand
our mailbestandonze mailbestand
your mailbestandjouw mailbestand
every mailbestandelke mailbestand
which mailbestand?welke mailbestand?
a big mailbestand / the big mailbestandeen grote mailbestand, de grote mailbestand