The Illinois Certificate of Mailing or Publication is an official document issued by the state of Illinois that confirms an item has been sent by mail or published in a newspaper. The certificate serves as proof of mailing or publication and can be used in court or when filing documents with the state. There are two types of Illinois Certificates of Mailing or Publication: the Certificate of Mailing and the Certificate of Publication. The Certificate of Mailing is used to show that an item has been sent by mail and includes the sender's name and address, the recipient's name and address, the date of mailing, and the item sent. The Certificate of Publication is used to show that a notice has been published in a newspaper and includes the newspaper's name and issue date, the page and column numbers of the notice, a description of the notice, and the date of publication.