Not if you did it mistakenly and without a criminal intent. Take your first opportunity to return it to the carrier or the post office though.
If you accidentally open mail that is not addressed to you, you should reseal it and write "Return to Sender - Incorrect Recipient" on the envelope. Then, drop it back in the mailbox so it can be delivered to the correct recipient. It is important to respect others' privacy and not read or keep mail that is not meant for you.
up to 12 months in prison
The opening and closing salutations for an email should use exactly the same criteria as other mail. It depends on the formality of the mail and to whom it is addressed.
No, it is illegal to open mail that is not addressed to you.
Yes, tampering, hiding, removing, or opening mail not addressed to you, before it is delivered to the intended addressee, is a federal crime.
No, it is not legal to open mail that is addressed to your house if it is not intended for you.
It is illegal to open mail that is not addressed to you, even if it is sent to your address.
It is technically a federal crime to open someone else's mail. Enforcement is up to the descretion of the US Postal Service and other federal agencies.
You cannot legally demand the mail not originally addressed to you and can put you into legal hurdle.
No, it is illegal to open mail that is addressed to someone else, even if it is delivered to your house.
If they are acting within the scope of their employer-authorized capacity, AND one of their duties is opening the company mail, yes, they may. Exception: The above is true if the mail is clearly addressed to the BUSINESS itself. If the letter is clearly PERSONALLY addressed directly to the owner of the business, they would have over-stepped their employer-assigned bounds if they opened it, and even if no legal action was contemplated, they could be disciplined or terminated because of it.
While there may well be state laws that cover this, the big problem is that it is a violation of Federal Law (US Postal Regulations) to "intercept" mail addressed to others.