No, there isn't. Most prefer having more space, so I doubt that changes. However, I suggest using the contacts bar, as you can click the ones to cc and then just click the 'add to cc' button on that pane.

In the Copies & Folders section of Account Settings, check the boxes for Cc and Bcc, and leave the boxes blank (see picture).

That sounded interesting, but on the Mac it doesn't make any difference. Selecting a new message still does not show the CC and BCC fields.

Appreciate your kind reply. :)

It works here on W10, so perhaps try in safe mode (hold Option when launching TB). Also, note that this is a per account setting.

If it still doesn't work, there is an add-on that includes this as an option:

https://addons.thunderbird.net/en-us/thunderbird/addon/nostalgy_ng/versions/3.6.1

You are amazing! Thank you!!!

I just had to restart TB.

All working as expected now.

Thanks again.

In the Copies & Folders section of Account Settings, check the boxes for Cc and Bcc, and leave the boxes blank (see picture).

This is the correct answer. check de CC, and leave it blank, then appears ever.

Thanks a lot.