Minn. R. Civ. P. 5.01
Except as otherwise provided in these rules, every order required by its terms to be served, every pleading subsequent to the original complaint unless the court otherwise orders because of numerous defendants, every written motion other than one which may be heard ex parte, and every written notice, appearance, demand, offer of judgment, designation of record on appeal, and similar document shall be served upon each of the parties. No service need be made on parties in default for failure to appear except that pleadings asserting new or additional claims for relief against them shall be served upon them in the manner provided for service of summons in Rule 4. A party appears when that party serves or files any document in the proceeding.
Minn. R. Civ. P. 5.01