De or het missiebrief?

The correct Dutch article is:

de missiebrief

How to use missiebrief

the missiebriefde missiebrief
this missiebriefdeze missiebrief
that missiebriefdie missiebrief
our missiebriefonze missiebrief
your missiebriefjouw missiebrief
every missiebriefelke missiebrief
which missiebrief?welke missiebrief?
a big missiebrief / the big missiebriefeen grote missiebrief, de grote missiebrief