You may want to unsubscribe after viewing a few days of e-mails. If you don't unsubscribe properly you could be on a list for a long time and not want to be. If your e-mail program has a signature file, this should be disabled when trying to subscribe to most lists. The subscription information should be contained in the body of the e-mail with nothing after it. Do not sign your name in the body of the e-mail.
Every list seems to have common rules of etiquette.
You are not allowed to slander people, swear, bait people, or advertise a product. These are grounds for being removed from a list. Being a member of a list is not a democratic privilege, it is controlled by the list moderator. So for many people it is a test of their hospitality. In other words, if you enjoy the list, be polite and think before you write.