Each vote by mail voter's ballot that is mailed to an election authority absent a postmark or a barcode usable with an intelligent mail barcode tracking system, but that is received by the election authority after the polls close on election day and before the close of the period for counting provisional ballots cast at that election, shall be endorsed by the receiving authority with the day and hour of receipt, opened to inspect the date inserted on the certification, and, if the certification date is election day or earlier and the ballot is otherwise found to be valid under the requirements of this Section, counted at the central ballot counting location of the election authority during the period for counting provisional ballots. Absent a date on the certification, the ballot shall not be counted.
If an election authority is using an intelligent mail barcode tracking system, a ballot that is mailed to an election authority absent a postmark may be counted if the intelligent mail barcode tracking system verifies the envelope was mailed no later than election day.
In addition to the voter's signatures not matching, a vote by mail ballot may be rejected by the election judge or official:
If the election judge or official determines that any of these reasons apply, the judge or official shall mark across the face of the certification envelope the word "Rejected" and shall not cast or count the ballot.
A vote by mail ballot subject to this subsection that is determined to be valid shall be counted before the close of the period for counting provisional ballots.
If a vote by mail ballot is rejected for any reason, the election authority shall, within one day after the rejection, transmit to the State Board of Elections by electronic means the voter's name, street address, email address and precinct, ward, township, and district numbers, as the case may be. If a rejected vote by mail ballot is determined to be valid, the election authority shall, within one day after the determination, remove the name of the voter from the list transmitted to the State Board of Elections. The State Board of Elections shall maintain the names and information in an electronic format on its website accessible to State and local political committees.
Upon request by the State or local political committee, each election authority shall, within one day after the request, provide the following information about all rejected vote by mail ballots: voter's name, street address, email address and precinct, ward, township, and district numbers, as the case may be.
10 ILCS 5/19-8