Sec.[Section] 1. Be it enacted by the people of the state of Illinois represented in the General Assembly, That in all suits instituted against any incorporated Company in this state, a summons returned executed on the President thereof or served by leaving a copy of the summons with the Principal Clerk, Cashier[,] or Secretary of such Company at his Office within such time and under such regulations as are or shall be provided by law for the service of such process in suits against natural persons shall be deemed a sufficient service whereon to ground subsequent proceedings and Judgment against such Company in any Court of this state having jurisdiction: Provided that the provisions of this act shall not be construed to interfere with any mode of suing counties or other corporations specially provided in any statute law of this State.