I assume you mean to ask what to do after you get this email? The answer is do not respond and ignore the empty threat. The scammer bought your old password and user id/email along with many others and massmailed this threat to everyone. Your password was leaked in one of the many breaches of a 3rd party site and is now for sale online. The scammer uses it to try to scare people to pay. If you fall for it you will likely be a target of even more scams in the future as you will be added to so-called 'sucker lists' sold among scammers. Go to https://haveibeenpwned.com/ to check if your email has been exposed in a breach and read details about it.