To configure Confluence to send outgoing mail:
Go to Confluence Settings > Questions & Answers > Mail Server Settings
Enter your SMTP mail server details: hostname, port, user name, password, …
3. Click Save to save your settings.
Click on Test button > Enter email address, subject, message > click Send to send a test message with your Mail Server Settings
To receive email notifications when there are new questions, users need to watch Confluence spaces
To receive email notifications when there are any answers or comments on a question, users need to watch that question