• Check the permissions for the domain in the current tab in "Tools > Page Info > Permissions"
• Check that images are enabled: Tools > Options > Content: [X] Load images automatically
• Check the exceptions in "Tools > Options > Content: Load Images > Exceptions"
• Check the "Tools > Page Info > Media" tab for blocked images (scroll through all the images with the cursor Down key).

If an image in the list is grayed and there is a check-mark in the box "Block Images from..." then remove that mark to unblock the images from that domain.

There are also extensions (Tools > Add-ons > Extensions) and security software (firewall, anti-virus) that can block images.

• https://support.mozilla.com/kb/Troubleshooting+extensions+and+themes

Images or Animations do not load

• http://kb.mozillazine.org/Images_or_animations_do_not_load
• https://support.mozilla.com/en-US/kb/Images%20or%20animations%20do%20not%20show

Check and tell if its working.

Thanks for your efforts, but the only graphics that do not display are embedded in e-mail received. The graphics will display when the mail is replied to or forwarded.

Images in Messages do not appear

• http://kb.mozillazine.org/Images_in_messages_do_not_appear

Check and tell if its working.

Thanks for the suggestion, but View->Message body as-> does not appear in this version of Firefox. Still stumped.

Problem solved. Tools, options, content, load images, exceptions. Thanks to all.