Listsource data incomplete?

[Eric Narciso]

Hi.  I am doing a bunch of yellow letters and I got a list from listsource.  I was going through the data, and I found that "owner 1 label name" "owner 1 first name/last name"  Some of these fields were empty, or it looked like, they were backwards.  Sometimes it had the name of a trust, or just a last name, etc.  

Anyway, how do you make it look like a "personalized" yellow letter if its printing up name backwards or wrong names, etc?  Is there a way to filter out these people on listsource (or any method to get this fixed)?  And I never would've noticed, had I sent it to a company to write and mail them (which I will do next time). 

Is there a way to fix it?  I had a lot of Chinese names, and wasn't sure if they were in the order of first, then last name.  I saw that there were a few average names that were obviously backwards.