The Kesser Shem Tov 2:pg.536 writes that the minhag of London and Amsterdam is to read the Megillah without the taamim (cantillation). This minhag is also found in Alger and Ashkanaz. The reason that is given is that the megillah is called a letter (not sure how that explains this). The Rivevos Ephraim 4:173:44 thinks this is a chiddush.
Do any communities or shuls read the megillah without the cantillation nowadays (I have never seen or heard this before)?