I suggest you create a small thumbnail to embed into the message, and just attach the real images.

An alternative would be to embed the images and then resize the display of them using the image properties dialogue. But I suspect the images will be of greater use to you sent as attachments. They arrive with a simple "save as" option, whereas an embedded message needs to be selected, copied and saved. It's a more manual process and more error prone.

The fundamental problem with the add-on is that it is designed to reduce the size of the email message (plus attachments) by actually resizing the image itself. But you want the image to arrive at its full size and at full quality, so this add-on is of no use to you.

If you are likely to be moving large files frequently, I suggest you look at the filelink option, use Dropbox or set up an ftp server.

Thanks Zenos. When I embed the image I do resize the display. But the problem comes when I send the image as an Attachment, which I often need to do. But when I do that, thunderbird always adds the image inline in the body of the email, as well as an attachment, and it always shows as a very very large image in the email body. So I'm trying to find a way to control the size of that image that TB automatically shows in the email body, whenever I attach an image file. It's disruptive to the reader and makes the email look not as professional as I need it to be.

The "auto resize image" was the only add-on I found that looked like it might work, but you're right, it doesn't do what I need. I was hoping there was some other option.

You do realize that it is Thunderbird displaying the attachments, not some feature of email.

Unless your recipient is using Thunderbird they are unlikely to see them until they open the attachments. What most people will see is what yu see if you turn the option off in Thunderbird.

On the toolbar > view > Display attachments inline

Thanks all for the information.