I've been using muttng over mutt for the last few months. Basically, the idea boils down to the fact that there's been quite a few really useful mutt patches available for some time, but fewer and fewer of them were being added into the main mutt tree.

Finally, some folks got fed up with this, forked mutt, and imported a bunch of patches. It's hard to say for sure, but at least 15-20 patches are in there now, on top of everything that mutt already does.

Of course, you could get much of this functionality in standard mutt by applying these patches yourself... go ahead and try though, trying to get 15-20 patches to apply and not clash is quite a task :-)

Some of the more interesting features that I make use of now are header caching -- which means opening a folder with several thousand emails no longer takes 20 seconds to open (my sent mail, some 6600 messages, took that long).

It offers a sidebar, not unlike the folder list found in Thunderbird/Evolution/Outlook/etc... you can show and hide it with a single key combo, and it allows you to flip through your various mailboxes in a hurry, without actually having to flip screens by hitting 'c', then '?', then browsing.

They also went through, and made a number of "sanity" changes to the config file syntax. For example, mutt seemed to flip between using 'pgp_*' and 'gpg_*' for various config options. Muttng renamed them to the more sane 'crypt_*' (oh the irony).

And just a tiny little thing that makes a world of difference to me is the menu context patch. If you're in a folder with 100's or 1000's of messages, and you find yourself scrolling up or down through a bunch of them for whatever reason, the messages themselves only begin scrolling once your cursor hits the top of bottom of the screen. So, it's really easy to flip past the one you want. Sure, right after it slides by you scroll back down, and open it with no problem. But what if it were even easier? The menu_context option says not to scroll messages when the cursor is at the top or bottom of the screen, but instead, when it's N messages from the top of bottom of the screen. I have mine set to '5'.... meaning there are *always* at least 5 messages above and below the cursor (unless you're at the beginning or end of the mailbox, of course)

Simple pleasures, perhaps. But, anyone who knocks it just hasn't had the opportunity to use a mail client that allows you to tweak absolutally every aspect of it :-) Indeed, that may be it's one primary fault as well, the fact that you can tweak every option :-) Once you take the time to sit down and do it though, it's really hard to beat.

Oh, and muttng can act as a news reader too, but I haven't yet had a chance to try this out.