Maybe it's an American thing, but for us Europeans, a message beginning simply with "Team,..." instead of something like "Dear Team,..." sounds rather, let's say, disrespectful. You'd only do this in the military.
To me, "Team" sounds very English, while "Liebe Mitarbeiter(innen)" would sound very German.
Just checked my email: One "Hi Team," and one "Team,". Someone is disrespecting me!