Usenet Explorer

Which settings in Newsgroups>Properties for a newsgroup to only retrieve new headers do I need to set (and which values)?

I would assume that upon adding a newsgroup, it would

retrieve all headers the first time

then next week it would retrieve only the headers not yet retrieved while keeping the existing headers, read or unread as well as not loading any existing header that have been deleted.

Thanks

You can set Retention/Dates to "Natural" and "Headers per server" to "All".