This section is used to configure newsgroup specific options.
|•||Download newsgroup body|
You should only download message bodies immediately if you want to monitor the article text for entered keywords. In all other cases it doesn't make really sense since the check takes longer and more data must be downloaded. Using that option means that you also download bodies for postings you aren't interested in.
If you only want to monitor a newsgroup for new postings and replies, then you should not use the "download bodies" option. The check is faster then and bodies are downloaded automatically when you open an article.
When you create new newsgroup bookmarks, the server configuration is entered by the bookmark assistant and can be changed in that section. If username/password is required, you have to enter them in the Server Authentication section.