Yes... but some antibodies are lost in refridgerated milk and more antibodies and enzymes are lost in frozen milk.
I am an exclusively pumping mom too. I have enough milk to feed triplets (believe me having an oversupply is just as bad as not having enough milk!). I don't want to waste the milk the freezer, so I make my 11 week old drink 5 oz of frozen milk everyday then breastfeed or refridgerated milk for other meals. This way I get to work and he also get the antibodies he needs.