Mozilla thunderbird has a really nice distinction that i wish more places had: new vs unread messages.
New messages are ones that have just shown up in your inbox, and refreshing the inbox will make them no longer new.
Unread messages will stay unread until you read them (or mark them as read)
This distinction is quite nice to have pointed out, expecially for long threads where all the messages have the same subject.
@binarycat yep! all new messages have a ✨ next to them while unread messages are in bold and have a 🟢 in the unread column.
A Plan 9 oriented server.