How do I increase the font size when creating a new Outlook email?

When I create a new email in Outlook the font is so small that I can hardly read it. See the snip below. (When the snip appears in the Forum, the font size looks much bigger than it actually is.) Is there any way that I can increase this please?

My Outlook version is 2107, Build 14228.20226 Click-to-Run and in case it's relevant my Windows version is 19043.1151



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Perhaps I should tell you that I paid £49.99 at the beginning of July to upgrade to Outlook. (This subscription expires on the 20th January 2023.) I immediately had many problems so I created a thread in the Microsoft Community. A Microsoft Agent & Moderator there told to me to run SARA and below is a snip of what it found. It seemed clear to me that Microsoft had sold me a product that isn't fit for purpose so I asked the Forum Owners for advice in mid-July. I haven't had a reply to date.