10 ILCS 5/19-6
Such vote by mail voter shall make and subscribe to the certifications provided for in the application and on the return envelope for the ballot, and such ballot or ballots shall be folded by such voter in the manner required to be folded before depositing the same in the ballot box, and be deposited in such envelope and the envelope securely sealed. The voter shall then endorse his certificate upon the back of the envelope and the envelope shall be mailed in person by such voter, postage prepaid, to the election authority issuing the ballot or, if more convenient, it may be delivered in person, by either the voter or by any person authorized by the voter, or by a company licensed as a motor carrier of property by the Illinois Commerce Commission under the Illinois Commercial Transportation Law, which is engaged in the business of making deliveries.
Election authorities shall accept any vote by mail ballot returned, including ballots returned with insufficient or no postage. Election authorities may maintain one or more secure collection sites for the postage-free return of vote by mail ballots. Any election authority with collection sites shall collect all ballots returned each day and process them as required by this Code, including noting the day on which the ballot was collected . Ballots returned to such collection sites after close of business shall be dated as delivered the next day, with the exception of ballots delivered on election day, which shall be dated as received on election day. Election authorities shall permit electors to return vote by mail ballots at any collection site it has established through the close of polls on election day. All collection sites shall be secured by locks that may be opened only by election authority personnel. The State Board of Elections shall establish additional guidelines for the security of collection sites.
It shall be unlawful for any person not the voter or a person authorized by the voter to take the ballot and ballot envelope of a voter for deposit into the mail unless the ballot has been issued pursuant to application by a physically incapacitated elector under Section 3-3 or a hospitalized voter under Section 19-13, in which case any employee or person under the direction of the facility in which the elector or voter is located may deposit the ballot and ballot envelope into the mail. If the voter authorized a person to deliver the ballot to the election authority, the voter and the person authorized to deliver the ballot shall complete the authorization printed on the exterior envelope supplied by an election authority for the return of the vote by mail ballot. The exterior of the envelope supplied by an election authority for the return of the vote by mail ballot shall include an authorization in substantially the following form:
I............ (voter) authorize............... to take the necessary steps to have this ballot delivered promptly to the office of the election authority.
....................... .......................
Date Signature
..............................................
Printed Name of Authorized Delivery Agent
....................... .......................
Signature of Authorized Delivery Agency
....................... .......................
Date Delivered to the Election Authority
10 ILCS 5/19-6