If you are talking about mailing someone then yes it is illegal not to mention highly dangerous.
yes
No, it is not illegal to send money to yourself.
Yes. but not if the person receiving it asked you to send it
It is a crime to send any illegal substance through the mail.
It's actually illegal to send cash through U.S. mail. But alternative options are a money order, a visa (in the form of a gift card) or a personal check!
It is not illegal to buy or to consume snus in the UK but it is illegal to sell it
No, but it is illegal to receive money for the files.
No, it is not illegal, but it is extremely annoying.
Yes, it is illegal to send a fake lawyer letter as it constitutes fraud and can lead to legal consequences.
Yes, it is illegal to send unsolicited emails without permission, as it violates anti-spam laws.
Yes, it is illegal to send nudes as a minor because it is considered child pornography and can have serious legal consequences.
Yes, it is illegal to send nudes to a minor as it is considered child pornography and can result in serious legal consequences.