Mac Mail: How to insert text BETWEEN attached photos in an email?

Send rich text emails and then you get this:

You can select Rich Text in the Format menu.

Now here's a secret: It really doesn't matter. Email is a very crude form of communication, for all it's ubiquity. There is no guarantee that what you carefully craft on your machine will look anything like that at the other end. How it appears on that machine is entirely dependent on the settings on the receiver's end.

You have to use the arrows to move the cursor between and then hit return. You don't see the insertion point when you do, you just have to watch where it is in the steps.