Mozilla Thunderbird image files

[shankle]

Recently my wife got an e-mail with about a dozen attached *.gif/*.jpg files in it.
Thunderbird went blah blah when trying to read them. I tried detaching them and
putting them in My Documents. I downloaded "Lviewpro" and this let me view them.
BUT, I really shouldn't have to go through all this to read a *.gif/*.jpg etc.
Part of the problem was that it wanted to keep going back the Internet explorer.
I finally found out how to make it go to Mozilla Firefox.

I usually don't mess with this kind of stuff so I am sure I am missing the obvious.
Thanks for any help,
JPS