> In modern times, you can see this very same concept used at craigslist wherein CL maps your email address to a random craigslist email address, allowing you and another party to have painless email back-and-forth without leaking identity

CL implementation is flawed and only gives perception of privacy. I forget the header/tech name for it, but if you hit reply and your email account is set to “First Last <[email protected]>” it will pass along that entire string to the recipient in the body of the email. The obfuscation is only in the actual email address the message goes through