Each pleading, other than initial Petition and Summons, filed with the court clerk shall contain a certificate of mailing signed by counsel stating that a true and correct copy of the pleading was mailed to each attorney of record or, if a party is unrepresented, to such pro se party at their last known address. Such certificate of mailing must show the date of mailing and must be signed by the attorney filing such pleading. Failure to attach the certificate of mailing may result in the hearing being continued.