How about you review and make the changes on the original file in its original location before attaching it? That's how I would normally do it.

You are correct that this would work; it's just that I seem to catch a lot of errors right before I send the message.

What Stan suggests is the ONLY way it will work correctly.

When I am ready to send the file as an attachment, I attach the file

At this time Thunderbird takes the file and converts it to a mime encoded representation of itself and includes iti n the email.

and click the attachment,

And here Thunderbird takes the MIME encoded representation of the file and converts is back into it's binary representation and saves it to the temp folder so it can be opened

to give it one final review before sending. Sometimes I do notice an error and I make the changes and re-save the file.

As I explained above, you are not editing the original file, you are editing the temporary one created just because you chose to edit the attachment (which is not actually a file anymore, that is what MIME encoding does, makes it into text)

Today I noticed that when I clicked the file attachment I noted that the path listed for the file was a temp folder. After making a change, I went out the message and went to look at the file, the file in the folder (where I put it originally not the temp folder) was not changed.

The last time the original file will be accessed is when you click attach. There are other more subtle security/audit trail issues with having a mail client replace the original file as well. Given that the replacement would need to be a copy and replace it may actually errase records of previous editing. Not an issue at home, but possible quite important in some business and government environments where recording who did what and when is considered a legal requirement.

What I was expecting was to be able to make the change and save it to the same location where it was originally so that the copy I send as an attachment and the copy I have would be the same.

While I understand where you are coming from, that is not how email works. Email can not transmit binary attachments, everything has to be text, so MIME encoding is a necessary step to send any non text attachment to convert it to text for sending.

I can understand the use of a temp folder when the file is not on the PC but it is strange that Thunderbird would make a new copy and place it in a temp folder.

With the knowledge that an attachment is not a file and not in the same form as it was when you selected attach I hope you can understand that creating a temp file is actually the most appropriate approach to the problem. Especially as the email does not contain the path to the original file. (how embarrassing if you are corresponding with some politician and the path in the email save moron in DA's office. Good thing just the file name is sent, although Word document often do contain path names to images and templates which actually can represent a security risk in their own way.)

I hope I have explained this well enough; I have been using Thunderbird for years and love it!

And I hope I explained the process enough that you understand why what you thought would happen never will.

Excellent explanation. Now that I understand that I will only make changes in the origional location of the file. I really appreciate all your help with this.

Thanks so much.