This information comes from your email provider.  If you are unsure of the settings, contact your provider for assistance or do a Google search for them. Example: If I'm using @yahoo.com email, I would do a search for "Yahoo SMTP settings".

• The Outgoing server is: smtp.gmail.com 
• The Authentication Type is always Login.
• The username is your full email address. Ending in either @gmail.com if free account or @yourdomain.com if paid account. 
• The password is the app password you setup in the Gmail account.  This guide will give you directions:  How to setup an app password in Gmail
• The Port is: 587
• Security is: Use TLS

Once you have the correct settings, hit the Test email settings button.

If you get the successful message, KC has been configured properly and you are ready to use any email function in the program.

If you get an error, you'll need to allow your Google account to allow third party programs like KC to use their email server. 

G Suite/Workspace (paid email account) users, please see this guide: Enabling G Suite to allow third party software to send emails

Once you have enabled less secure apps, please go back to KC and test email settings again. If success, you're good to go. If still error, please see this guide: Error Gmail Still Blocking Account Access After Enabling Less Secure Apps