Rated 4 out of 5 stars

This extension does exactly what I wanted, but not in the best way. I am not sure if it is possible, but making it a mouse hover-over instead of adding more columns would be ideal. Or, allowing both: Additional column(s) and/or hover-over. (If you are not clear on what I mean: You should be able to hover over the "From:" field and see the @sender/email addr). Yahoo webmail is a good example.)

This review is for a previous version of the add-on (1.0.4).