While there isn't a traditional ".exe" installer for a Gmail desktop app, you can "download" Gmail into to create a seamless, app-like experience on your computer. By using Chrome’s "Install page as app" feature, you can access your inbox directly from your taskbar or desktop without navigating through browser tabs. How to Install Gmail as a Chrome App
Transforming Gmail into a standalone application takes less than a minute. Download and install Google Chrome - Computer gmail download chrome