To the extent that a power of attorney expressly grants an agent authority over the content of electronic communications sent or received by the principal and unless directed otherwise by the principal or the court, a custodian shall disclose to the agent the content if the agent gives the custodian:
1. A written request for disclosure in physical or electronic form;
2. An original or copy of the power of attorney expressly granting the agent authority over the content of electronic communications of the principal;
3. A certification by the agent that the power of attorney is in effect; and
4. If requested by the custodian:
a. A number, username, address, or other unique subscriber or account identifier assigned by the custodian to identify the principal’s account; or
b. Evidence linking the account to the principal.