I live in apartments and each building has a row of mailboxes at the front of each building, with a box for each apartment (there are no flags to raise). We do not have a separate drop box for outgoing mail. I had always assumed the mailman was to take outgoing mail, but I have put a bill in my box before and it sat there for three days before I finally just took it to the post office myself because it was going to be late, assuming he didn't open my box because I had no incoming mail. But last week I tried to mail something else, and it sat in there again, but this time incoming mail was being put in and the mailman just was not taking my outgoing mail. Is this something I need to ask a local post office, or what? Thanks!