Forms will auto-fill with constituent data after users click links in email messages, if "Use email links to autofill forms" is marked under the Administration > Sites & Settings > General > Email Settings in BBIS. This setting only works for email messages that sent to query-based email lists that use constituents as the data source. When you include links to forms in query-based emails, the program pulls data from constituent records even when users are not logged in to your website.

The setting auto-fills forms with biographical details such as name, title, primary address, phone number, and email address. The setting applies to forms that you create with Donation Form, Email Forwarding Form, Event Registration Form, Event Registration Form (Classic), Membership Form, User Email Preferences Form, and User Login parts. It does not apply to forms that require users to log in because email links do not bypass login requirements. 

Warning: If a recipient forwards a query-based email and someone else follows a link from the email message to a web form, the original recipient's biographical details auto-fill on the form.

Note: Disabling this setting will affect new emails. It is not a retroactive change.