(1)    A limited liability partnership or registered foreign limited liability partnership may be served with any process, notice, or demand required or permitted by law by serving its registered agent. The department may serve any written notice required or authorized under this chapter by e-mailing it to the registered agent’s e-mail address on file with the department, and such notice shall be effective as provided in s. 178.0103 (6).

   (2)   Except as provided in sub. (3), if a limited liability partnership or registered foreign limited liability partnership has no registered agent, or its registered agent cannot with reasonable diligence be served, the partnership or foreign partnership may be served by registered or certified mail, return receipt requested, or by similar commercial delivery service, addressed to the partnership or foreign partnership at its principal office, as shown on the records of the department on the date of sending. Service is perfected under this subsection at the earliest of the following:

      (a)    The date the partnership or foreign partnership receives the mail or delivery by the commercial delivery service.

      (b)    The date shown on the return receipt, if signed on the behalf of the partnership or foreign partnership.

      (c)    Five days after it is deposited in the U.S. mail, or with the commercial delivery service, if correctly addressed and with sufficient postage or payment.

   (3)   If process, notice, or demand in an action cannot be served on a limited liability partnership or registered foreign limited liability partnership pursuant to sub. (1) or (2), service may be made by handing a copy to the individual in charge of any regular place of business of the partnership or foreign partnership if the individual served is not a plaintiff in the action. If the address of the partnership’s or foreign partnership’s principal office cannot be determined from the records of the department, the partnership or foreign partnership may be served by publishing a class 3 notice, under ch. 985, in the community where the partnership’s or foreign partnership’s principal office or registered office, as most recently designated in the records of the department, is located.

   (4)   Service of process, notice, or demand on a registered agent must be in a written record.

   (5)   Service of process, notice, or demand may be made by other means under law other than this chapter.