I wonder which features you see as bells and whistles? The last change I would see this way was the addition of Chat ('instant messaging") for which I have no use so I simply ignore it. On, and maybe the new menu system, which again I don't much care for, so simply ignore it. My point is that if you can be a bit more specific about what you don't like, maybe someone can offer advice on working around it. We do have users who like you see no advantage in updating from a version they are comfortable with. Whilst I can't agree that Thunderbird simply gets better with each release, I also have to say that in general it gets no worse. So my main incentive to keep it up to date is for the fixes to security-related issues. If a fault has been found that makes it vulnerable, then I want the latest version which addresses said vulnerability. So yes you can decline the update. Under Tools|Options you can find settings for updating and there turn off the checking for updates.