Well I guess you have that out of your system now. At least I hope so as this is a support forum, not an appropriate location for feedback. Feedback needs to be directed here https://connect.mozilla.org/ I don't like supernova so just don't bother telling me what you think of it. We will probably agree but it is not germane to a support topic. Now to address the last topic first. Downgrading is perhaps the worst thing you can do. It almost guarantees you will loose data of some sort because the profile data storage formats have changed in the new release however we can work towards making the new release at least usable. Unfortunately I have to ask you for information as you initial post, whilst containing plenty if invective and emotion, contains very little useful information from a diagnostic perspective. So lets just back up. I have been hanging around these support forum for more than a decade, and my observation is the vast majority of "utter failures" to function post update actually have nothing to do with Thunderbird and everything to do with security software. Primarily Antivirus software firewall, antivirus scanners and sometimes VPN's. a simple test of their involvement is to restart Thunderbird and then the operating system in troubleshooting mode/ safe mode. The Thunderbird troubleshooting mode is the quickest and easiest, and primarily exudes rogue add-ons that have caused issues post update. Unfortunately this also includes components "injected" into Thunderbird from security software. But it is a rather important first step. The operating system safe mode is more time consuming, but unfortunately is about the only way to get a clean benchmark against which to determine if the problem is Thunderbird or other software. *Restart Thunderbird with add-ons disabled (Thunderbird Safe Mode). On the Help menu, click on "Restart with Add-ons Disabled". If Thunderbird works like normal, there is an Add-on or Theme interfering with normal operations. You will need to re-enable add-ons one at a time until you locate the offender. *Restart the operating system in '''[http://en.wikipedia.org/wiki/Safe_mode safe mode with Networking]'''. This loads only the very basics needed to start your computer while enabling an Internet connection. Click on your operating system for instructions on how to start in safe mode: [https://support.microsoft.com/en-us/help/12376/windows-10-start-your-pc-in-safe-mode Windows 10], [http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode Windows 8], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-7 Windows 7], [http://windows.microsoft.com/en-us/windows/start-computer-safe-mode#start-computer-safe-mode=windows-vista Windows Vista], [http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/boot_failsafe.mspx?mfr=true" Windows XP], [http://support.apple.com/kb/ht1564 OSX] ; If safe mode for the operating system fixes the issue, there's other software in your computer that's causing problems. Possibilities include but not limited to: AV scanning, virus/malware, background downloads such as program updates. It would also be quite beneficial if you actually supplied the error message you see when attempting to get mail or send it as well as a copy of your troubleshooting information so we are not guessing about account type or settings. To this end could you please do the following? # Open the menu '''[[Image:Fx57Menu]] > Help > Troubleshooting Information''', then click '''Copy text to Clipboard'''. # Go to https://pastebin.mozilla.org/, paste the clipboard by right clicking in the large text area, select paste from the menu, change the retention period to expire in 28 days, use the '''Paste Snippet''' button to create a page containing your info, then copy the resulting URL (address) of the page created. # Open a reply to this post, and paste the URL to your troubleshooting information you just copied.