Gmail Change Font. Change the font in the browser. Changing font size—Click the font size drop-down list to see the four different sizes in Gmail.
Open Appearance Settings by clicking the Start button and then clicking Control. Now your Gmail theme should change to the image you selected. Open Gmail and select settings then general settings.
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Now your Gmail theme should change to the image you selected.
Has any encountered an issue where Gmail is changing font colors for phone numbers and address? Gmail allows you to select from several basic fonts while you're composing your message. Recently my gmail view randomly changed from one I can read, to very tiny font.