Originally Posted by chucker
What does mdutil -s say?
I know almost nothing about Terminal commands, but the ones listed on that page I linked to seemed to do the trick.
(I put that one above in, and nothing came back.)
I left the computer alone for 12 hours, and it seems like the Spotlight reindexing went well.
I can find emails in Mail again, and all seems right in the world.
Thanks for your help Chucker.