Md. Code, Estates and Trusts § 15–608

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 a court, a custodian shall disclose to the agent the content if the agent provides the custodian:

(1) A written request for disclosure in a 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, under penalty of perjury, that the power of attorney is in effect; and

(4) If requested by the custodian:

(i) A number, username, address, or other unique subscriber or account identifier assigned by the custodian to identify the principal’s account; or

(ii) Evidence linking the account to the principal.