This is a public forum, so posting your e-mail address here is not a good idea. I'm going to assume that you mean you cannot open e-mails in Thunderbird, not files. Please post two things here in a reply so I can understand what is going on: 1. A screenshot of your entire Thunderbird window, showing your Folders on the left side, and a list of e-mails on the right side. Use a picture editing program like "Paint" to blur or block out any personal information. [https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem How do I create a screenshot of my problem?] 2. Your Troubleshooting Information from Thunderbird: Press the Alt key or F10 key on your keyboard to show the Thunderbird menu. Thunderbird menu: Help: Troubleshooting Information Click the "Copy text to clipboard" button. Paste (Ctrl-V), the text into your response here.