First, the obvious thing is to check that Thunderbird is set to show messages as HTML, not plain text. This is necessary to see some images, though ordinarily, pictures would be shown as attachments if the message is displayed in text mode.

It's possible that the image is inserted into the displayed email using a script and Thunderbird doesn't run scripts. If so, you may have to get your ticket via webmail (in your browser) or by using another email client.

What were you looking for in the Config Editor? Is not generally necessary to go there to fix image display problems. BTW, mine has many mailnews entries.

Thanks Zenos, On my iphone and on my Macbook I can see the barcode but not in the display of e-mail in Thunderbird on my desktop which is connected to the printer. My messages are displayed full html. I even added extension for full body display and installed true barcode fornts. But nothing seems to work.

I have been reading the net for solutions and one of this suggested to go to Config: editor and edit the mailnews ...   to set to false. But my config.editor does not have even one mailnews entry.

Hope some one will come up with some solution.

No mailnews? Dozens here...

We still don't know what you're trying to change. I doubt it will help you anyway.