Here, you can choose your preferred font size, from small to huge.
To change these preferences in the Mail app on your Mac, choose Mail Preferences, then click Fonts & Colors. Whether the reason is lesser eye strain, or simply a nicer layout, here is how you can change the font size when using Gmail: Changing the overall font size One of the many handy customization options that Gmail offers is also the ability to change the font size in your emails, and make day-to-day correspondence that much simpler. From allowing you to stay synced on all of your devices to giving you plenty of personalization options, Gmail still reigns supreme among its competitors. Gmail is one of the most widely-used email clients around the world, and for a great reason.