Currently, both Mail and News accounts are listed in the same window. You cannot read mail and read from newsgroups simultaneously. There should be an option to seperate the listing of Mail and News accounts into seperate window instances of MailNews. Thus I could read my Mail in one window, and read from newsgroups in another. This idea could be extended, so that for each account regardless of type, can be shown in a seperate window. For example, a window for IMAP mail, a window for POP mail, and two windows for seperate news accounts. Having the backend code seperated out like this could easy the architecural limitations we have seen in bugs about the Subscribe dialog locking users out from reading mail, etc.  You can double-click on a folder to load a new MailNews window, but then you could load, read and delete messages from the same source in two seperate windows. The could create inconsistencies and havoc.
There's not a hope in hell of getting this done in the 1.0 timeframe, so I'm futuring myself. Adding arch and helpwanted keywords. Maybe with Seth's huge biglist comes down...
To make it even more unreachable, this is an RFE :)
as you mentioned, you can just open a second mailnews window. there are some bugs about certain things not working correctly when you have multiple 3 pane windows. For example, dnd from one 3 pane to another is probably broken. But simple news reading and posting in one 3 pane, and reading and responding to your Inbox will work fine. If you find problems with multiple 3 panes, please log bugs. I don't think this is a valid bug. james, can you elaborate?
OK I guess this comes down to whether or not you like clutter :-) In 4.x I hated the way I could browser Mail, or News, never both simulateously. If there was a way of opening two mailnews windows, it didn't present itself to me. In Mozilla, I pull up MailNews, and see that I can choose which Mail OR News account I wish to inspect. The same problem applies here as did to 4.x - you can only view one account at a time. That is unless you happen to have found that double-clicking an account folder opens a brand new MailNews window. 1. The "double-click the folder to get a new MailNews 'view'" is bad. Not many people will realise that, and some will not bother using the product because of the 'one account at a time' user interface. 2. If you could click twice on the MailNews icon in the taskbar, or the Tasks menu item, then that could elliviate the problem, but again it requires the user to try it. Many users that we are trying to reach don't try the same gui feature more than once unless it makes sense. You could argue that two MailNews windows makes sense, but it would have to argue with popular usage opinion. A problem exists with the suggestion of simply opening a second window to access your accounts. If you're like me, and have one desktop for each task you are doing (IRC, Web, Mail, News, development, for instance), you may be drawn from the MailNews windows to another desktop, come back, and see that you were using Account xyz (perhaps news), and now you want Account 123 (mail); so you click on your mail account folder and read it, perhaps send some mail, delete old mails. But wait! I see in my Windows / GNOME / KDE / Whatever taskbar, that I already had a window open for that... Oops, is it dead, out of sync, or am I going to crash? People need the simplicity of turning each MailNews window into one specifically for each account. Having multiple accounts in each window might look pretty in screenshots, but when you are knee-deep in accounts, it could get tricky knowing which window you want (although the same could be said for one-account-per-window). If there was a nice menu system that clearly displayed each window with it's account name, so you could switch between them, I think it would solve the issue. Lemme add mpt for his input on this.
bah, in nc4 there were lots of ways to end up w/ multiple windows. i currently have 4 mailbox windows, 1 mail composition and two newsfeeds. of course one mechanism relied on collabra aka netscape message center [press <backspace> in the folder view]. 1. mail & newsgroups>window settings [x] double clicking a folder or newsgroup opens a new view. <- iirc we have something like this implemented. 2. the component bar of nc4 was rather whacked [there are a few bugs about it in bugzilla] clicking inbox would open a new window for inbox unless one was open in which case it focused. clicking news would open a new window for the default mail server unless one was open in which case it focused. clicking the inbox button from the inbox window would just check mail. it wouldn't be hard to restructure bookmarks to let you bookmark a folder/server/account/newsgroup so people could manage windows by using bookmarks (and it wouldn't be hard to change the entire menu interface to be rearrangable based on user dnd via the bookmarks ui -- but mpt wouldn't like this). mpt probably also wouldn't like growing the tasks menu to show additional accounts -- iirc he's still trying to kill it.
Unfortunately, Timeless is unhealthily fond of using the word `kill' when he means `rename'. (See also bug 81752 2001-05-20.) ... But I digress. > 1. The "double-click the folder to get a new MailNews 'view'" is bad. Not > many people will realise that, and some will not bother using the product > because of the 'one account at a time' user interface. This seems fallacious. Surely the 5 percent of people who prefer the clutter of multiple windows for their mail/news reading are almost exactly the same 5 percent of people who can work out how to choose `Tasks' > `Mail' a second time, or to double-click on a folder or an account in their first window. The following are valid bugs, and should be filed separately: (1) choosing `Tasks' > `Mail' a second time doesn't open a second window (hopefully covered by bug 20306); (2) double-clicking on an account doesn't open a new window; (3) the folder pane can't be shown/hidden in windows (I think Timeless is working on that somewhere alrady). Apart from those, this bug is WORKSFORME.