In Mozilla’s Thunderbird email client, the default says that every email that has images from the web is going to have it’s images blocked, and you have to enable the remote content BY email address.
This can be really annoying. If you are pretty secure in your email manhood and don’t fear the web, you can disable this feature pretty easily:
Go to Tools > Options > Advanced > and click the Config Editor button
In the search box type in “mailnews.message_display.disable_remote_image and it should show a setting in the box below that is set to true. Double click the word true to change it to false and then close it.
Now you will always see remote images in emails. Easy!