Make sure you can send a personal message that does not go back to the whole list. Test your method with something simple and non- controversial to a close friend who can confirm it was a personal message and did not go to the list. There is nothing more embarrassing than sending a personal note to a colleague and later learning it was sent to everybody. Listen and absorb for a while to catch the tenor of a new list. Most lists don't encourage personal replies to the whole list, but some do.
Some lists are very busy, some are indolent.
Hopefully someday all lists will have the digest and index features. It's a searchable database of mailing lists you can root through via keyword, much like a traditional online search service. You'll also find a generous amount of supplementary information on the history of mailing lists and lots of links to other resources. If this does not work, you will receive an error message. Finally, your command will be automatically cancelled if you do not confirm it within 72 hours.