Large, ANNOYING FONTS when composing a New Message

I’ve been using the same Outlook email program for decades. I think a new version came out 2 -3 years ago, but I didn’t like it, so I stayed with the one I’ve been using for years. I think it’s called Outlook Classic.

About two weeks ago, a new and bizarre problem popped up. I’m not sure, but I’m guessing it’s related to A.I.

What is the problem? When I compose a new email message, instead of seeing my usual font, the font is about 3 or 4X larger than my normal font. It is literally gigantic. Why is that showing up instead of my normal, default font?

However, after I hit the SEND button, it goes the message is delivered using my default font. 

I’ve tried everything I could think of to get rid of this annoying, frustrating problem. I’m sure I’m not the only person with this problem.

Is there a simple solution which will bring back my normal font when composing email messages?

Thanks!