RULE 4.5 INADVERTENT TRANSMISSION
(a) A lawyer who receives a document relating to the representation of the lawyer's client and knows or reasonably should know the document was inadvertently sent shall:
(1) promptly notify the sender, and
(2) comply within a reasonable time with the sender's request, if accompanied by a promise of reimbursement of any out-of-pocket expense involved, that the lawyer return the document.
(b) For purposes of this rule, "document" includes facsimile transmissions, electronically received messages, and metadata retrievable from an electronic transmission.
(c) For purposes of this rule, a document was inadvertently sent if the sending was a deliberate though mistaken act or resulted from the ignorance, negligence, or inattention of the sender or the sender's agent.
(d) A lawyer who receives a document under the circumstances creating a duty under this rule does not violate Rule 1.2 or Rule 1.4 by not communicating to or consulting with the client regarding the receipt or the return of the document.
 This Rule recognizes that lawyers sometimes receive documents that were mistakenly sent or produced by opposing parties or their lawyers, or by third parties. If a lawyer knows or reasonably should know that such a document was sent inadvertently, then this Rule requires the lawyer to promptly notify the sender in order to permit that person to take protective measures. Whether the lawyer who receives a document that was sent inadvertently is required to take additional steps, other than notification and return of the document if requested and reimbursement of expenses is promised, is a matter of law beyond the scope of these Rules, as is the question of whether the privileged status of a document has been waived.
 Some lawyers may choose to return a document unread. The decision to voluntarily return such a document unread is a matter of professional judgment reserved to the lawyer, and the lawyer is not required to communicate with or consult with the client about that decision.
Reference: Minutes of the Joint Committee on Attorney Standards on 08/06/04, 09/24/04, 06/14/05.