Creating Adobe PDF Files with Form Fields - Adobe InDesign CC - page 504

2 . To enable the viewer of a PDF form to return a filled-out form, use the Buttons
And Forms panel to assign the Submit Form action to the button. After you assign
the Submit Form action, enter mailto: followed by an email address (for example,
mailto:[e-mail]) in the URL field.
3 . You can open and fill out PDF forms using Adobe Acrobat or Adobe Reader. Adobe
Acrobat also offers additional features for working with PDF form fields.