This little tip just changed my life… I swear. I've been looking FOR-EV-ER for a way to filter my Thunderbird Inbox so that I see only the "starred" messages. Despite my poking and prodding and searching I couldn't figure out how until today.
When you're building your filter/custom view/folder criteria, "starred" is not an option in the first drop down (like Flag, Tags, and Junk Status are). Additionally, despite the fact that the mail server knows all about whether a message is "starred" or not, it's not in the header of the email either
In Thunderbird, Starred is a STATUS!
That's right, a STATUS. Drop the first box down and select "Status", drop the second box down and select "is", then drop the third box down and select "Starred". That's it, you're done.