Undeletable incoming message in Kmail (KDE3)

Yesterday a message arrive, and appears in the inbox showing the correct 
date, but it is stored at the very bottom of the Order of Arrival column, 
as it is older than messages that arrived months ago. It is shown with an 
empty body; View > Headers > All headers also shows no headers, but the 
Message List window knows its Subject, Sender, Receiver, and date/time of 
arrival. I have found no way to delete it: an attempt to do so causes a 
strikeout line to appear through it, but the message remains in the 
message list; after a time, the strikeout is gone, and the message itself 
continues to be displayed in the list as before (as Unread).

How can I remove this ghost?

-- 
Stan Goodman
Qiryat Tiv'on
Israel