For users having Gmail as email service can find details here. The details here are subject to change by Google as per their discretion.
For users having Outlook and any other email service, can contact system administrator of their respective organization.
To apply SMTP settings go to Admin Panel >> Tools >> Integration >> SMTP Settings

Another option to apply SMTP setting is through Execution Wizard. Make sure that you have checked Show Advanced Settings option to show Advanced Execution Settings page having SMTP Settings.

Important Points you need to know for SMTP Configrations:
- Use valid and active email address for sending and receiving emails with an automation process in place for handling email bounces.
- Ensure that the SMTP server details entered are authenticated and allows only authorized users to send emails.
- Test SMTP account settings before sending real email.
- Use a separate dedicated IP address for your SMTP server.
- Optimize the email content to include only informative details in a readable format, with an appropriate subject line.
- Attach the execution report in a suitable format to be easily viewed by the client such as PDF or HTML.
- Use SSL or TLS encrypted connections to prevent eavesdropping and data tampering.