Windows Live Mail keeps giving me the ‘new mail’ alert for messages sent to trash.

In windows live mail, when a new mail arrives in my spam folder, and I delete it without reading it, it moves to the trash folder.  Several minutes later, I get a new mail alert (both a sound and the icon in the task bar).  It's really annoying as I end up having to check my mail many times each day to find there is nothing actually new.  My questions are, is this normal behaviour, and is there a way to fix it so that deleted mail does not trigger an alert.

Thanks in advance.

Ric.