notifications not emailing admins or moderators

Hi, i have enabled the notifications from the backend for 'Notify admins on new posts' and 'Notify moderators on new posts' but neither seem to send an email to the joomla administrator or moderators. The email settings are working as they send the user registration details. I have added an email account into the 'email parser' section and tested, but does not make a difference. Regards James