RULE 4.4: RESPECT FOR RIGHTS OF THIRD PERSONS
(a) In representing a client, a lawyer shall not use means that have no substantial purpose other than to embarrass, delay, or burden a third person, or use methods of obtaining evidence that violate the legal rights of such a person.
(b) A lawyer who receives a document relating to the representation of the lawyer's client and knows or reasonably should know that the document was inadvertently sent shall promptly notify the sender.
 Responsibility to a client requires a lawyer to subordinate the interests of others to those of the client, but that responsibility does not imply that a lawyer may disregard the rights of third persons. It is impractical to catalogue all such rights, but they include legal restrictions on methods of obtaining evidence from third persons and unwarranted intrusions into privileged relationships, such as the client-lawyer relationship.
 Paragraph (b) recognizes that lawyers sometimes receive documents that were mistakenly sent or produced by opposing parties or their lawyers. 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 is required to take additional steps, such as returning the original document, 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. Similarly, this Rule does not address the legal duties of a lawyer who receives a document that the lawyer knows or reasonably should know may have been wrongfully obtained by the sending person. For purposes of this Rule, "document" includes e-mail or other electronic modes of transmission subject to being read or put into readable form.
 Some lawyers may choose to return a document unread, for example, when the lawyer learns before receiving the document that it was inadvertently sent to the wrong address. Where a lawyer is not required by applicable law to do so, the decision to voluntarily return such a document is a matter of professional judgment ordinarily reserved to the lawyer. See Rules 1.2 and 1.4.
Model Rule 4.4
Reporter’s Explanation of Changes
Paragraph (b): Add material on obligations of lawyer upon receipt of inadvertently sent document
Numerous inquiries have been directed to ethics committees regarding the proper course of conduct for a lawyer who receives a fax or other document from opposing counsel that was not intended for the receiving lawyer. ABA Standing Committee on Ethics and Professional Responsibility Formal Opinion 92-368 advised that the receiving lawyer is obligated to refrain from examining the materials, to notify the sending lawyer and to abide by that lawyer’s instructions. That opinion has been criticized, in part because there is no provision of the Model Rules directly on point. The Commission decided that this Rule should require only that the lawyer notify the sender when the lawyer knows or reasonably should know that material was inadvertently sent, thus permitting the sending lawyer to take whatever steps might be necessary or available to protect the interests of the sending lawyer’s client.
 A phrase has been added to this Comment identifying "intrusions into privileged relationships" as among the third-party rights a lawyer must respect.
 This new Comment explains the obligations imposed by paragraph (b). It makes clear that the Rule does not address possible additional obligations of the lawyer that might be imposed by other law. Nor does it address the legal duties of a lawyer who receives a document that the lawyer knows or believes may have been wrongfully obtained by the sending person. Finally, the Comment explains that, for purposes of the Rule, the term "document" includes e-mail or other electronic modes of transmission.
 This new Comment lends support to those lawyers who voluntarily choose to return a document unread when they know or reasonably believe that the document was inadvertently sent. The Commission believes that this is a decision ordinarily reserved to the lawyer under Rules 1.2 and 1.4 and that a lawyer commits no act of disloyalty by choosing to act in accordance with professional courtesy.