I’ve only recently switched to using Gmail for my main email account, and am benefitting on a few fronts e.g. spam reduction, the handy “promotions” tab, better/easier filtering and so on.
One thing that really annoyed my though were the font-sizes when viewing emails and typing replies. The “settings” for the Gmail web interface leaves quite a lot to be desired here. There aren’t many ‘view’ options, and there’s confusion in terms of the font setting really relating to the HTML styling when composing emails rather than being a ‘view’ option. Yes, there’s ‘cosy’ and comfortable’ and ‘compact’ but all this really changes is the line spacing.
Looking at options to customise the fonts/sizes (for inbox, reading font size, and the quick reply box font) I ended up installing a browser app called ‘Stylish’ and experimenting with an override stylesheet. Of course this is a bit of a fiddle and only applies to one machine but it does seem to be the best way to properly control the Gmail interface in terms of fonts.
‘Stylish’ allows users to upload their CSS ‘styles’ for others to install and use, so in the spirit of sharing solutions, here’s my little bit of Gmail CSS if you want to do the same:
https://userstyles.org/styles/134406/google-gmail-inbox-font-styles-with-comments