Home » Other » What does a Certificate of Mailing – Firm Look Like? What does a Certificate of Mailing – Firm Look Like? admin 06/09/2017 Other No Comments PS Form 3665 is used as Certificate of Mailing — Firm that looks like this: Tweet Pin It Related Posts What does an Operation Santa Letter (Individual) Look Like? What Does an Application for Post Office Box Service Look Like? What Does a Certificate of Mailing Look Like? Leave a Reply Cancel reply Your email address will not be published. Required fields are marked *Comment Notify me of follow-up comments by email. Notify me of new posts by email.