If you select 'Reply' then that means only reply to the sender, so you should only see one TO email address - the person who sent the email.

If you select 'Reply-All' then it should pick up all the email address, the person who sent the message and those who were cc'd.

You've misunderstood my question. I was referring to the attached message you are replying to. For example, you get a message with 10 people cc. When you either reply or reply to all it only attaches the message with "John Smith wrote". It does not show all of the others that were copied.

After selecting 'Reply-all': Confirm that this is not a viewing issue. Is there a scroll bar on the left side hiding all the other email addresses?

Could you test to see if this is being caused by an addon extension.

Start Thunderbird in Safe Mode. 'Help' > 'Restart with addons disabled' or close thunderbird and hold down 'Shift' when you click on TB icon to startup.

In Safe Mode, try to 'Reply-all' to see if the Cc's are now populating the TO fields.

If it is now working correctly, you need to restart TB. Then access the addons: Tools > Addons or Menu icon > Addons

click on 'Extensions' icon - looks like a jigsaw piece. Disable each in turn and test to see which one is causing the issue.

This addon was known to cause this issue, but there may be others: 'Display Contact Photo 1.2.6'

Why do you leap to answer WITHOUT reading my problem even after I stated you misunderstood ? Please READ my concern before once again answering about a completely different problem.

Ok I'm with you now.

It's quite logical when you think about it. If you use 'Reply' then the person who sent the email, does not need to know who they sent the email to. If you use 'Reply-all', then all who got the original with get the response. In both of these cases all the relevant information is also displayed in the headers.

So if you used 'Reply-all' then in your Sent folder, that sent email would display all of those email addresses in the headers, therefore it is not necesary to display all the information twice.

However, if you 'forward' an email to a third party who say was not initially involved, but will be from now onwards, then all the details /email addresses you are refering to will be in the attached lower section below reply.

You may think it's logical, but (as I stated), OUTLOOK does not do this. The "attached" message you are replying to (whether or not you REPLY or REPLY TO ALL) always shows all of the original receivers of the message in the attachment.

There must be a way of having TB do the same thing, rather than only showing "John Smith wrote on DATE & TIME" above the attached message you are replying to.

I think one or the other of these add-ons will help you by including the original message's headers.

https://nic-nac-project.org/~kaosmos/realborders-en.html https://nic-nac-project.org/~kaosmos/changequote-en.html

But I am confused by your reference to an attachment in the phrasing of your query. Do you really expect an email client to parse attachments?

Replies generally include the text of the original message. Where does an attachment fit into a reply?

Forwarding is another matter. The original message can be quoted inline or sent as an attachment. In the second case, your recipient should see it as you did. The inline version will be as inserted by your email client, which may or may not include its headers. These add-ons may give you control over that.

I used "attached message" (for lack of a better term) to refer to the "text of the original message" that appears below the reply.

You are right if you FORWARD it does exactly what I want, but there must be a switch that I don't know about to allow this same sort of thing to happen when REPLYing or REPLY TO ALL ?

So you haven't tried either of the suggested add-ons?

This one: https://nic-nac-project.org/~kaosmos/changequote-en.html will quote the original header.

I get the error message "your connection is not secure". GO BACK

I have been using that site for so long that I forget that I set up an exception.

Does this one work better?

https://freeshell.de/~kaosmos/changequote-en.html

That works great, and now it does exactly what I wanted.

Thanks Zenos !