On Wed, Feb 26, 2014, Aaron Poffenberger wrote: > I tried that. If you telnet into smtpd to manually send an email and set > "rcpt to: <user>" you will receive a "553 Recipient address syntax
That's invalid even if you gave a proper address. RFC 5321: RCPT TO:<forward-path> [ SP <rcpt-parameters> ] <CRLF> ... Since it has been a common source of errors, it is worth noting that spaces are not permitted on either side of the colon following FROM in the MAIL command or TO in the RCPT command. The syntax is exactly as given above.