I'm pretty sure there has been. I remember one time when I answered a question, after thinking about it I deleted the post so that somebody could give a better answer. The delete post button looks like a sheet of paper with a trash can in front of it. When you hit the icon it tells you that only the message author or board moderator may delete the post. I thought that it maybe only available when the posting has never been read so I created the test message and tried to delete it but edit was the only option available. But I'm almost positive I've had the option to delete some of my own posts in the past.