2. Create or edit a signature file (generally "signature 1.mht") under X: \ program files \ foxmail \ signatures. 3. Save the mht file. 4. You can see the signature in Foxmail file, but you still can't edit the signature in mailbox management signature. Method 2: Uninstall IE9 update, and finally you can edit the signature directly in the mailbox management signature. It seems that the real reason is that Foxmail can't edit the signature because IE9 is compatible. Official answer: The following instructions apply to Windows 7 and Windows Vista. 1. Click the Start button, type programs and features in the search box, and then click View Installed Updates. 2. Right-click Windows Internet Explorer 9, click Uninstall, and then click Yes when prompted. 3. Click one of the following options: * Restart immediately (complete the uninstallation process of Internet Explorer 9 and restore the previous version of Internet Explorer). * Restart later (waiting for you to shut down or restart the computer).