If the envelope had someone else's name and not your name, you should in theory not have opened it, and should instead have marked it "Not known at this address. Return to Sender." and handed it back to the postal service to be returned.

If you were asked to sign for the letter, ideally you would check that it is not addressed to you (or anyone else now at your residence) and refuse to sign, but it is easy to overlook that at the moment a letter is presented to you. And sometimes certified mail is delivered without obtaining the signature of any resident.

If, however, the envelope had your name on it, you were entitled to open it, and are not bound by any confidentiality statements in the cover letter, assuming that you had no previous relationship with the sender. You may well choose to respect them, but you cannot be legally bound unless you accepted such an obligation at some point, usually in a contract of some sort. If you did have a confidential relationship with the sender, then its terms would normally control, whatever they might be.

You could prepare an envelope addressed to the sender, enclose the document, and mail it back to the sender. You could optionally add a short cover latter explaining how you received the document. If the envelope was addressed to some other person, this would, I think, be the best thing to do. If the document was addressed to you, this is totally optional, you could legally just discard the document and forget about it, and you can probably legally read it and do whatever you like about the contents. But as the answer by gnasher729 points out, returning it would be the nice thing. As the comment by Makyen points out, you may wish to retain evidence of what was received.

One sided confidentially statements on letters or faxes are not legally effective in the absence of some prior or current relationship or agreement to be bound in confidence.

If the envelope had someone else's name and not your name, you should in theory not have opened it, and should instead have marked it "Not known at this address. Return to Sender." and handed it back to the postal service to be returned.

If you were asked to sign for the letter, ideally you would check that it is not addressed to you (or anyone else now at your residence) and refuse to sign, but it is easy to overlook that at the moment a letter is presented to you. And sometimes certified mail is delivered without obtaining the signature of any resident.

If, however, the envelope had your name on it, you were entitled to open it, and are not bound by any confidentiality statements in the cover letter, assuming that you had no previous relationship with the sender. You may well choose to respect them, but you cannot be legally bound unless you accepted such an obligation at some point, usually in a contract of some sort. If you did have a confidential relationship with the sender, then its terms would normally control, whatever they might be.

You could prepare an envelope addressed to the sender, enclose the document, and mail it back to the sender. You could optionally add a short cover letter explaining how you received the document. If the envelope was addressed to some other person, this would, I think, be the best thing to do. If the document was addressed to you, this is totally optional, you could legally just discard the document and forget about it, and you can probably legally read it and do whatever you like about the contents. But as the answer by gnasher729 points out, returning it would be the nice thing. As the comment by Makyen points out, you may wish to retain evidence of what was received.

One sided confidentially statements on letters or faxes are not legally effective in the absence of some prior or current relationship or agreement to be bound in confidence.

If the envelope had someone else's name and not your name, you should in theory not have opened it, and should instead have marked it "Not known at this address. Return to Sender." and handed it back to the postal service to be returned.

If you were asked to sign for the letter, ideally you would check that it is not addressed to you (or anyone else now at your residence) and refuse to sign, but it is easy to overlook that at the moment a letter is presented to you. And sometimes certified mail is delivered without obtaining the signature of any resident.

If, however, the envelope had your name on it, you were entitled to open it, and are not bound by any confidentiality statements in the cover letter, assuming that you had no previous relationship with the sender. You may well choose to respect them, but you cannot be legally bound unless you accepted such an obligation at some point, usually in a contract of some sort. If you did have a confidential relationship with the sender, then its terms would normally control, whatever they might be.

You could prepare an envelope addressed to the sender, enclose the document, and mail it back to the sender. You could optionally add a short cover latter explaining how you received the document. If the envelope was addressed to some other person, this would, I think, be the best thing to do. If the document was addressed to you, this is totally optional, you could legally just discard the document and forget about it, and you can probably legally read it and do whatever you like about the contents.

One sided confidentially statements on letters or faxes are not legally effective in the absence of some prior or current relationship or agreement to be bound in confidence.

If the envelope had someone else's name and not your name, you should in theory not have opened it, and should instead have marked it "Not known at this address. Return to Sender." and handed it back to the postal service to be returned.

If you were asked to sign for the letter, ideally you would check that it is not addressed to you (or anyone else now at your residence) and refuse to sign, but it is easy to overlook that at the moment a letter is presented to you. And sometimes certified mail is delivered without obtaining the signature of any resident.

If, however, the envelope had your name on it, you were entitled to open it, and are not bound by any confidentiality statements in the cover letter, assuming that you had no previous relationship with the sender. You may well choose to respect them, but you cannot be legally bound unless you accepted such an obligation at some point, usually in a contract of some sort. If you did have a confidential relationship with the sender, then its terms would normally control, whatever they might be.

You could prepare an envelope addressed to the sender, enclose the document, and mail it back to the sender. You could optionally add a short cover latter explaining how you received the document. If the envelope was addressed to some other person, this would, I think, be the best thing to do. If the document was addressed to you, this is totally optional, you could legally just discard the document and forget about it, and you can probably legally read it and do whatever you like about the contents. But as the answer by gnasher729 points out, returning it would be the nice thing. As the comment by Makyen points out, you may wish to retain evidence of what was received.

One sided confidentially statements on letters or faxes are not legally effective in the absence of some prior or current relationship or agreement to be bound in confidence.