This is the message that I get:

System Error Occured: Negative seek offset

Trace:
java.io.IOException: Negative seek offset
	at java.io.RandomAccessFile.seek(Native Method)
	at com.popmail.folder.Folder.delete(Compiled Code)
	at com.popmail.Session.move(Compiled Code)
	at com.popmail.Session.move(Compiled Code)
	at com.popmail.servlet.http.PopMailSession.doPost(Compiled Code)
	at com.popmail.servlet.http.PopMailSession.service(Compiled Code)
	at com.popmail.servlet.http.PopMailSession.service(Compiled Code)
	at javax.servlet.http.HttpServlet.service(Compiled Code)
	at com.popmail.httpd.Post.go(Compiled Code)
	at com.popmail.httpd.Request.run(Compiled Code)