Viewing jpg in Thunderbird

I use Thunderbird for email and I have gimp installed for image processing. When I open jpg attachments in Thunderbird they are opened in gimp, but I would like to view them in eog normally since it opens faster.

When I do Edit->Preferences->Attachments->View & Edit Actions it doesn't display any extensions and I can't add any.

Any ideas?
I just stumbled across this old post and you can correct that behavior by making sure that eog is the default for opening jpegs(How depends on your desktop environment) instead of gimp. Also you may need to go into the Thunderbird Preference menu and choose "Ask me where to save every file". That will allow you to click on the attachment and choose to open or save it and if eog is the default for jpegs and you select open it will open in eog.