Whatever John, i remember similar issue happened to my wifes' KMail.
Me myself i use Thunderbird, but my wife uses KMail for many years already.
Her posts arrived also into the Wastebasket, but we sorted it out somehow.
I have to dig into my memory to find out, for i didn't documentate.
There is a workaround, i am sure.
Let you know, whenever i get the right brainwave.
Meanwhile, maybe an idea to pop-up your question into the KDE-forum?