10 ILCS 5/23-1.4a

Upon receipt of a properly executed Petition of State Election Contest and the filing fee, the Clerk of the Supreme Court shall within 48 hours (a) mail, by certified first class mail, return receipt requested, a copy of the Petition to each candidate and each election authority listed in the Petition at their addresses shown therein and to the State Board of Elections, and (b) notify the Chief Justice of the Supreme Court that a Petition of State Election Contest has been filed.