With Christmas less than a week away, Mainers packed the posted office Monday. Postal Service officials expected the day to be the busiest mailing day of the holiday season. Folks lined up at the post office in downtown Bangor to get their gifts one step closer to their final destinations. Officials expect about 800 million pieces of mail to be handled Monday nationwide.That’s a 40-percent increase from the average daily volume.Shippers we talked to Monday say they’re not worried about their presents making it in time for Christmas.Kristin Thom of Buckport says, “No, I’m not actually. This one in particular, it wouldn’t matter if it’s a little later. But I still think it’ll be there before Christmas.”Sara Martin says, “No – my family always expected to get their gifts late from me – hahaha!”Officials say Monday is the busiest day for mailing packages. The busiest day for cards is Tuesday.The Postal Service expects to deliver 16.5 billion letters, packages and cards between Thanksgiving and New Year’s Eve.