I can't have Confluence sent notification emails locally. Although I've configured a valid SMTP server and could sent the TEST email successfully... I'm using a firewall here so easily can catch whenever a piece of software is trying to send any email. But no attempt is done by Confluence on the specific events we've configured (edit/create page/space, add comment, attach file).

NOTE: The user account has a valid email and is configured to receive notifications by email.