No, google SMTP accepts the RCPT TO with 250 "I'll try my best" regardless of th...

tyingq · on May 8, 2017

Nope, it doesn't do that.

  >RCPT TO: <someaccountthatdoesnotexist@gmail.com>
  550-5.1.1 The email account that you tried to reach does not exist. Please try
  550-5.1.1 double-checking the recipient's email address for typos or
  550-5.1.1 unnecessary spaces. Learn more at
  550 5.1.1  https://support.google.com/mail/?p=NoSuchUser j63si2824869ybj.160 - gsmtp
  >RCPT TO: RCPT TO: <john.baker@gmail.com>
  250 2.1.5 OK j63si2824869ybj.160 - gsmtp

arpa · on May 8, 2017

Ah! You're right, my bad, I was thinking about VRFY command!