https://blog.thunderbird.net/2024/08/maximize-your-day-templates-to-the-rescue/

Thanks Rick. Have now got a template in a folder called Templates and can create a new message from it. However I can't paste in a value to [PASTE HERE]. It just overwrites it. (Your animation doesn't show how) I did say an idiot's guide!

When you paste a value into [PASTE HERE], don’t you want it to write over [PASTE HERE]?

Sorry should have made it clearer. I am seeing [PASTE Hello World HERE]. I was assuming the [PASTE HERE} should disappear when I typed into it.

[PASTE HERE] does not work as that kind of placeholder. It's just boilerplate text.

You'll want to select what you want to replace before you type over it or paste over it.

I would not use brackets because selecting them requires more effort. If you use one word in capital letters as text to be replaced, you can select it by double-clicking on it. Whatever you type or paste next will replace it.

Example: "Dear NAME,"

Double click on "NAME". Then type or paste what you want to replace it with.