What happens if you "Paste without formatting", Ctrl+Shift+V  ?

The problem with copying from a word processor document is that you are copying word processing code, which when pasted into an HTML editor like Thunderbird, often gets unexpected and unwanted results.

If it was me and wanted to investigate this specific issue, I would look at the source (HTML) code in Thunderbird in the e-mail right after the paste, to see what in the HTML is causing the double spacing.

The addon ThunderHTMLedit adds a tab to the composition to let you see the HTML of the e-mail you are writing.

Bruce, When I "paste without formatting," all 30 areas with formatting (bold, underlined, colored) disappears, so I would have to re-create that formatting. Thunderbird has had no problem accepting Word text for years until the last Thunderbird update a few days ago, Thunderbird can handle Word text just fine if Mozilla reverses the design error in their last update.

I'll look into the ThunderHTMLedit addon.

There is more on this here.

It is a shame that we who try to help people here, have to check every single post they are going to reply to, to see if the poster posted it twice.

chris98597 You wasted my time by posting your request twice.

This is from the Forum rules and guidelines: "Create one thread and only one thread for each subject you need help with."

This is so you don't waste people's time, thus pissing them off.

Unfortunately, Mozilla neglected to provide a means to edit existing posts, so I had to add information with a second post. In the future, if Mozilla still neglects to add the common feature allowing posts to be edited, I will better distinguish the posts so it's easier to tell that the second post is an edit of the first. Sorry for the inconvenience.

When I am logged in and look at any of my previous postings, I see an "Edit this post" button.

But very often it is not helpful to edit an old message, particularly if you remove or change something that someone else has later commented on.

Why not just add to your existing thread? Or at least, if you're trying to kick it off again with a new thread, refer back to the original thread. This helps those trying to assist not repeat previous advice.

I have advised of the combination I used where I was unable to reproduce the problem you have. It seems to me that you may have stumbled over a particular combination of OS and versions of Thunderbird and Word where your problem is seen. Right now, we don't know how to reproduce your problem.

chris98597 said

Unfortunately, Mozilla neglected to provide a means to edit existing posts,...

See screenshot below.