[X-Newbies] Two Mail Threads Buried in One

[Al Poulin]

In Mail, with the View>Collapse All Threads selected, I frequently 
cannot find a specific thread listed that I know exists in my Inbox or 
a subject folder.  When I go to View>Expand All Threads, I find the 
thread items mixed into another thread.

This happens in particular with e-lists that I receive in feed mode, 
such as this X-NEWBIES list.

Why?  Can I fix this?

Thanks,

Al Poulin
Anger, hate, and revenge are for the devil, forgiveness is for God, 
proactive self-defense is for the rest of us.