BEMIDJI, Minn. — When Delbert Mikelson’s mail started showing up late — and sometimes not showing up at all — he blamed it on the opening of deer season.“I thought my carrier was out hunting,” Mikelson said over a breakfast of eggs and pancakes at Raphael’s Bakery Cafe in downtown Bemidji. But it wasn’t the buck hunt delaying the mail in Bemidji, a tiny town 100 miles south of the Canadian border where welcome signs are written in both English and Ojibwe and statues of Paul Bunyan and Babe the Blue Ox tower in downtown. Since early November, Bemidji has been bombarded by a sudden onslaught of Amazon packages — and local postal workers say they have been ordered to deliver those packages first.The result has been chaos at the Bemidji post office. Mail is getting backed up, sometimes for days, leaving local residents waiting for checks, credit card statements, health insurance documents and tax rebates. Routes meant to take eight or nine hours are stretching to 10 or 12. At least five carriers have quit, and the post office has banned scheduled sick days for the rest of the year, carriers say.