Currently Being ModeratedNov 20, 2012 7:09 AM (in response to janettefrombrazil)
Open Terminal in Applications>Utilities and paste this in. Then hit return.
defaults write com.apple.mail DisableInlineAttachmentViewing 0
To reverse the setting, change the 0 to a 1.
Currently Being ModeratedFeb 25, 2013 5:07 AM (in response to disguise)
thanx @disguise, this solved my problem too, I had Mail.app not displaying images anymore after migrating from my iMac to my MacBook Pro.