A defamation suit filed on behalf of a co-op tenant who was accused in fliers posted in the lobby of her building and in emails to the co-op board of owing a debt to the building should have been dismissed, an appeals court ruled Wednesday.

According to court papers, Irina Galanova, a resident of a co-op in the Brighton Beach section of Brooklyn and a member of its board of directors, alleged that fellow board members defamed her in emails stating that she was in arrears.