Sending emails via SMTP is a premium feature available in FloForms Pro version, which is recommended for better email delivery.
However, you also can set up SMTP independently with other tools.
Our friends over at WP Beginner have written a great article explaining how to use SMTP mail with Gmail, see the article linked below:
WP Beginner Gmail SMTP
The following tutorial explains how to use Mailgun for WordPress for your SMTP needs. It allows up to 10k emails a month, perfect for your photography sites contact form.
Mailgun for WordPress Tutorial