If I use "reply-to-all", icedove adds the original sender in the "To:"
field and the debian-user address in the "CC:" field. If I send it in
this way, will the sender receive two posts? I never received multiple
replies to any of my posts, so I think the list software probably
doesn't send out multiple copies to the same recipient. Am I correct in
assuming this?
No. If you send to two recipeints: the list and a person, the list
can't un-send your message to the person. You would have been sending
two. Mutt has a 'list reply' which only sends to the list. I don't
know about icedove.