Nothing shows up in the email, even after adding a tag to the form! How can I include a new field’s input in the email?

You need to add mail-tags to the fields in the Mail tab. These tags need to correspond to form-tags used in the Form tab. For example, when you used a form-tag [text your-new-field], the corresponding mail-tag that you should use in the Mail tab should be [your-new-field]. For more details, see How Tags Work.

Mail template sample

A mail-tag in the Mail tab will be replaced with the user input to the corresponding form field.

Just another contact form plugin for WordPress. Simple but flexible.