This is an SMTP protocol error log for virtual server ID 1, connection #920. The remote host "208.14.218.504", responded to the SMTP command "rcpt" with "550 5.7.1 Relaying to <DCary@abcd.com> denied (authentication required) ". The full command sent was "RCPT TO:<DCary@abcd.com> ". This will probably cause the connection to fail.