...
* the solution to my problem is typically to regenerate the indexes. To do
that, I go into the mail directory (.Mail, iirc, although you may have it
somewhere else), delete the existing indexes, and let kmail regenerate them.
...
Here, from directory ~/.Mail, is the ls -al listing for one (mbox) folder
(named tldp) with the three indexes. To start, you might want to experiment
with just one mail folder. Delete all three of the .index files, then
restart kmail (assuming you shut it down) and try to access the mail in that
folder. After a short delay, I'm hopeful that it will be ok.
-rw------- 1 rhk rhk 868526 Sep 19 16:05 tldp
-rw------- 1 rhk rhk 99043 Sep 19 16:05 .tldp.index
-rw-r--r-- 1 rhk rhk 937 Sep 19 16:05 .tldp.index.ids
-rw-r--r-- 1 rhk rhk 5425 Aug 24 07:28 .tldp.index.sorted