Hi. We noticed that the troubleshooting information was missing from these questions. In order to better investigate this issue, we may need to request a little more non-personal information. Please add the troubleshooting information to your post as well as the results of the following troubleshooting steps: * [https://support.mozilla.org/kb/use-troubleshooting-information-page-fix-firefox#w_accessing-the-troubleshooting-information-page Finding the Troubleshooting information] *Does Thunderbird work in TB Safe mode (see [http://mzl.la/1k5DWjq Thunderbird Safe Mode])? *What is the Thunderbird version? *What operating system do you use (e.g. Windows 7)? *Do you use anti-virus and firewall software? What is the version? *Do you use Thunderbird add-ons? *Who is the email provider? *Who is the internet provider? *What is the exact error message? *What steps did you take right before this happened? With this information we can better investigate and get a better idea of what may be causing the issue. Please post back with this information and any other questions you might have.