개발 공부 - Sendmail 오류(Relaying denied. IP name lookup failed)

이럴 경우에는 /etc/mail/sendmail.cf 의
R<TEMP>                        $#TEMP $@ 4.4.0 $: "450 Relaying temporarily denied. Cannot resolve PTR record for " $&{client_addr}R<FORGED>              $#error $@ 5.7.1 $: "550 Relaying denied. IP name possibly forged " $&{client_name}R<FAIL>                        $#error $@ 5.7.1 $: "550 Relaying denied. IP name lookup failed " $&{client_name}

부분을 주석 처리 한 뒤/etc/mail/access에 Connect:*.*.*.*      RELAY를 추가하고 (아이피를 고정시켜 놔도 되지만)/usr/sbin/makemap hash /etc/mail/access < /etc/mail/access를 실행한다.
service sendmail restart도 안 해줘도 되지만 해 줬음.