RCPT TO (Recipient To): Another command follows the 250 Okay reply code determining who the email is currently being despatched to. Once more, the SMTP server responds With all the similar code, at which point A further RCPT TO command might be despatched with a special receiver’s email handle. https://travisgpfnq.answerblogs.com/26874410/cloudflare-dns-server-an-overview