Chapter 4 Authentication : Managing Guest Access : Guest access in a retail environment : Creating an email harvesting portal
  
Creating an email harvesting portal
The customer’s first contact with your network will be with a captive portal which presents a web page requesting an email address. When FortiOS has validated the email address, the customer’s device MAC address is added to the Collected Emails device group.
To create the email collection portal
1. Go to WiFi Controller > SSID and edit your SSID.
2. Set Security Mode to Captive Portal.
3. Set Portal Type to Email Collection.
4. Optionally, in Customize Portal Messages select Email Collection.
You can change the portal content and appearance. See “Customizing captive portal pages”.
To create the email collection portal - CLI
In this example the wifi WiFi interface is modified to present an email collection captive portal.
config wireless-controller vap
edit freewifi
set security captive-portal
set portal-type email-collect
end