Rules of Professional Conduct
4. Transactions with Persons Other Than Clients
ER 4.4. Respect for Rights of Others
(a) In representing a client, a lawyer shall not use means that have no substantial purpose other than to embarrass, delay, or burden any other person, or use methods of obtaining evidence that violate the legal rights of such a person.
(b) A lawyer who receives a document and knows or reasonably should know that the document was inadvertently sent shall promptly notify the sender and preserve the status quo for a reasonable period of time in order to permit the sender to take protective measures.
 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 others. It is impracticable to catalogue all such rights, but they include legal restrictions on methods of obtaining evidence from others 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 a document was sent inadvertently, then this Rule requires the lawyer to stop reading the document, to make no use of the document, and 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 return such a document voluntarily is a matter of professional judgment ordinarily reserved to the lawyer. See ERs 1.2 and 1.4.