I wonder if it is a very large picture and Thunderbird is scaling the whole message down to fit it to the page?

Try this: set Thunderbird to show the message as plain text.

View|Message As|Plain Text

When you open the message, I'd expect you to see the text and the picture(s) separately as attachments(s). You can print the message text, hopefully at a reasonable size, and then print the pictures separately using Paint or Windows Image Viewer or whatever you have available to see pictures.

Some users seem to struggle with images. We occasionally see images posted here where it looks as if a picture has been pasted onto a larger sheet of paper and then an image of the whole sheet sent to us. Some users seem to think that you have to paste pictures into a word processor to manage them, then do a screen capture of the document.

When you open your stand-alone pictures in an image viewer, you will see if this has happened in your case.

This add-on:

https://addons.mozilla.org/en-GB/thunderbird/addon/printingtools/

may help with your printing experience. Maybe you can use it to coerce a given font size.

Thank you Zenos. However, this just happened recently (worked perfectly for years) and my other computer does not have this Thunderbird problem. I believe that there is place in Thunderbird where this can be corrected. I was told by my Canon Printer company that in other e-mail servers there is a place to resolve this by checking "Ignore the Font Sizes specified on the Web Page," but I cannot find such a check box in Thunderbird. Ed

re: Zenos comment: I wonder if it is a very large picture and Thunderbird is scaling the whole message down to fit it to the page?

This sounds likely as I've just tested this with an image that shows fine in the Message Pane, but it is actually bigger than a paper size, so it was shrunk to fit in the Scale. This left the actual text a lot smaller than desirable.

select the email. File > Print Preview or Menu icon > Print > Print Preview.

At the top of the 'Print Preview' window, you should see a 'Scale' option. Does it say 'Shrink to fit' ?

Try increasing the 'Scale' to increase the font. This will increase the text, but you may discover it also increases the size of the image so that not all fits.

You could then print off only the page numbers with text. then do Print preview again to get the images looking right and then only print those pages.

This situation does not occur all the time, it only occurs if the images are larger in size.

When I changed from Shrink to fit to 100%, the text and attached photo to the e-mail printed perfectly. Thank you, Ed K. Edward Lay Cary D. Langhorne Professor Emeritus of Architecture, University of Virginia Web Page http://www.people.virginia.edu/~kl2u/