Where do you guys get these ideas?
it's also illegal to send cash like, that
Not in the USA.
they can confiscate those money if they caught you to do so
Not in the USA. Who is "they" and why would they "confiscate" it?
1. Sending Cash via mail is illegal.
That is false.
2. It may not reach the destination.
That is unlikely.
3. Even if the receiver may scam you.
That is true.