Ill. Admin. Code tit. 23, § 475.30 – Requirements for Service of Documents

a) Unless otherwise provided for in this Subpart A, service of any documents may be made by personal delivery; by delivery through the United States Postal Service, postage prepaid, addressed to the last known address of the party; or by electronically using the party's email address. Service by electronic mail is preferred. Parties having access to email are encouraged to serve documents via email. The hearing officer shall set any parameters for the use of email to serve documents to ensure the service is completed properly.
b) The person serving the document shall certify to the manner and date of service in the following form:
I certify that I served the foregoing by (state method of delivery) on ___________________, 20___, addressed to the following at the address shown:
_______________________________________
Signature
c) If service is made by a non-attorney, the certificate of manner and date of service shall be subscribed and sworn to before a notary public.