I just went through this problem. Maybe your problem is different but here is what I did. Thunderbird blocks all images by default. In the message header block, there is a link that says something like "click here to show all images from this sender". This worked for me, but you have to do this for each sender you want to see images from. I hope this helps you.

Thank you for the message - unfortunately I don't have that option displayed in the header area of my messages at all (the only buttons are reply, forward, archive, junk and delete). Might this "display all images from this sender" you mention be something it's possible to activate from elsewhere in thunderbird, maybe?

Look at the bottom left corner, in the next block below. It should say, "always load remote content from ...". I think this message will only show in e-mails that have blocked pictures. You will have to do this for all senders that have blocked images. i know this is a frustrating problem, but don't give up. Good luck.

Many thanks again. No, that message doesn't appear in any of my emails, including those that clearly have images missing.

Maybe it's something wrong with the way I have thunderbird set up; I don't know. Unfortunately I wouldn't really know what settings to start looking at! :-\

I think the message you refer to used to appear, but not any more. (maybe a few updates ago)

I went on looking (just around the mozilla site) and found this:

If you can never see remote images because the "Show Remote Images" button is always missing check that permissions.default.image is set to 1 using the config editor. It was here that I saw it: http://kb.mozillazine.org/Privacy_basics_%28Thunderbird%29

and doing this seems to have solved the problem! (fingers x'd. So I thought I would post this link, just in case anyone happens by with the same difficulty as I had.)

Thanks again for trying to help; it's much appreciated.

Good for you. Persistence usually pays off. I didn't know about this before.