Refer: https://sourceforge.net/projects/msgviewer/
Unzip the file, and run
$ java -jar MSGViewer.jar
Picasa Replacement XNView MP
Good replacement for Picasa and you can set level of disk space used for Thumbnails. If you are going to use external drives you need to add them.
Refer: http://www.xnview.com/en/xnviewmp/