Only subscribers are allowed to post to this list. It's very simple. Your posting will be immediately distributed to all list members. This list is unmoderated. Postings are not screened before being distributed.
Postings are received by all members of the list, so discretion is needed.
Consider your postings as published material. I have a Hotmail account that I use when I'm not at home or in the office. Not unless you subscribe that account to the list. You can only post to the list from a subscribed email address. If you wish to use another address to post, that address must also be subscribed.