Forum OpenACS Q&A: How to setup the e-mail alert / notifications feature

As a newbie on OpenACS and having successfully installed OACS 4.5 / Postgre 7.2.3 / AOLServer 3.3, including ACS-Mail and ACS-Messaging, cannot find how to activate e-mail alerts. Is there a UI to configure or setup e-mail alerts/notifications? According to docs on 4.5, no notification package is needed. However in openacs.org, the notification package seems to be used yet. Thanks in advance for any help.