MathQuill for Gmail is a specialized browser plugin designed for Firefox that enhances the email composition experience by allowing users to easily edit mathematical formulas within their messages. By utilizing a graphical formula editor powered by MathQuill, users can insert and manipulate complex equations seamlessly. The functionality is straightforward: simply press Ctrl-M to access the editor, create or modify your formula, and convert it into an image with a simple key press. This tool is particularly useful for educators, students, and professionals who frequently communicate mathematical concepts via email.

The plugin integrates with the CodeCogs server to generate images of the formulas, ensuring high-quality rendering. However, users should be mindful of the usage limits, as generating over 3000 equations per day may require a commercial license. Additionally, while the app maintains privacy regarding the text of the email, it is important to note that the formulas are linked to the CodeCogs server, which may learn the content of the formulas created.