Password Reset Notifications on Manually managed account
After a manually managed password has been released, a notification will be sent out to the addresses specified in the notification field on the Managed Account to alert them to the fact that the current password is now Known. This is a security feature put in place to ensure that the Account in question does not become compromised. Since it is set to manual management, an admin will have to login to the web interface to manually reset the password.
You may receive notifications for one account and not other accounts depening on the current status of those accounts. Whether it is Known or not.
If you do not wish to receive these notifications, you will either have to manually reset the password so that it is no longer "known" or you will have to remove the email addresses from the notification field in the Account settings.