It seems that you have set "Keep replies in this folder" and at the same time you set on the server, so that server also send you your own posts. Either turn off the "Keep replies in this folder" in KMail or adjust configuration for your address on the mailing list server.
Thanks, I'll try that. That was not obvious to me.
Dashes separating the signature are useful to others - mail client through these dashes can automatically cut off signatures when replying. In any case - in configuration of KMail / Editor / Tepmlates you can set the template for the answers to the conferences.
I have looked in the templates. Removing the double dash was not obvious to me. Finally I figured out to disable global insertion of a signature and then just manually type my user name in the template after %CURSOR.
Darrell