In earlier versions of Thunderbird, the Enter key inserted a line break rather than creating a new paragraph. Now Enter creates a new paragraph and Shift+Enter inserts a break between lines in the same paragraph. This was changed to conform with the way most HTML editors work now.

If you prefer the old way, there is a checkbox for that in the Options/Preferences dialog:

Windows: "3-bar" menu button (or Tools menu) > Options Mac: "3-bar" menu button (or Thunderbird menu) > Preferences

At the top click Composition, then the General mini-tab

At the bottom of the HTML section, uncheck the box next to "When using paragraph format, the enter key creates a new paragraph" and click OK to save the change.

Success?

Thank you for your answer.

I am not too smart with computers, sorry. I got the the "Composition" the "General" tab, but don't see anything HTML, or the box you mention "When using paragraph format, the enter key creates a new paragraph" and click OK to save the change. So still have the same issue with emails!

Sorry I am stupid with these things. Elaine

https://support.cdn.mozilla.net/media/uploads/images/2016-05-02-22-59-34-93ae69.png

Thank you so much, so simple yet for me!!!!!!!!! Really appreciate your help, Elaine

Thanks. This works but the old/new check/uncheck works the opposite from your explanation. Not to worry though, it fixed it