The following settings use Gmail as an example, but they apply for webhost SMTP server as well.
From Email: your full Gmail address
From Name: name displayed in the emails sent (can leave black)
Mailer: select Send all WordPress emails via SMTP.
SMTP Host: smtp.gmail.com (if webhost, what they tell you to use; eg, mail.brownrice.com)
SMTP Port: 465 for use SSL encryption
Authentication: Yes, use SMTP authentication
Username: full email address same as From Email
Password: password from this email account
Reference Links
https://wpmaster.com/fix-gravity-forms-notification-email-not-sending/
