Collapse the righthand column
On desktop, the righthand column (Calendar, Starred, Contacts, Settings) takes up so much space, especially in a narrow browser window, that having the side-by-side message layout is basically unusable now. The message window is so narrow that many of my messages don't fit and have to side scroll, which is not ideal for reading. I never use the options in the righthand column, so there's just a big empty space that might as well be used for the message window. Collapse these icons when they're not being used, or even better: move them to the left column with everything else.
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