Malachi's rebuke is addressed to a corrupt priesthood. In addition to the moral-behavioral failings of which he accuses them, they don't bring "meat" into his house; if they did, he would open the windows of heaven to pour out a blessing on them.
It's impossible not to connect this passage with Malachi 1, where we learn that these same priests have polluted the Lord's "table" with contemptible "fruit," which is his "meat." What is this "fruit" and "meat"? It is "polluted bread," shrewbread not offered correctly, in accordance with the worship of the shalems.