method EmailKit.prototype.document EmailKit.prototype.document(unnamed 0: { subject: string; preheader: string; body: string; footer: string; }): string Returns the whole HTML document: the brand, the card holding body, and the footer. preheader is the hidden first line inboxes show beside the subject. Parameters unnamed 0: { subject: string; preheader: string; body: string; footer: string; } Return Type string