Even polite ones. Each post to an Internet mailing list is re-sent to all its subscribers. This can number in the thousands. In so doing, you not only advertise to the global community that you haven't a clue about Internet mailing lists but people have to wonder about your resourcefulness, your character, and possibly your parents' marital status. In a word, do not just hit reply to unsubscribe.
Mores are unwritten codes.
Sometimes they are unspoken. The underlying mores of the Internet require that you first do everything possible to solve a problem yourself before asking for help. I leave the rest to your imagination. As you have tried to solve the problem yourself by coming here, so I will do my best to give you the help you need. If I did, you probably posted an administrative request to a list to which I subscribe, or that I own.