DKIM 키 생성 및 적용

/ Unix/Linux/MacOS / 글쓴이 
1. 키 생성 (Selector 명을 mail123456으로 정의한 경우)
  mkdir -p /etc/opendkim/keys/mydomain.com
  cd /etc/opendkim/keys/mydomain.com
  opendkim-genkey -b 2048 -d mydomain.com -s mail123456
    ☞mail123456.txt 파일 내용을 네임서버 DKIM 부분에 적용
  chown -R opendkim:opendkim /etc/opendkim/keys/mydomain.com
  chmod 600 mail123456.private

2. opendkim 설정
  vi /etc/opendkim.conf
-----
Domain   mydomain.com
Selector mail123456
KeyFile  /etc/opendkim/keys/mydomain.com/mail123456.private

KeyTable      /etc/opendkim/KeyTable
SigningTable  refile:/etc/opendkim/SigningTable
InternalHosts /etc/opendkim/InternalHosts

UserID opendkim:opendkim
Canonicalization relaxed/relaxed
-----

  vi /etc/opendkim/KeyTable
-----
mail123456._domainkey.mydomain.com mydomain.com:mail123456:/etc/opendkim/keys/mydomain.com/mail123456.private
-----

  vi /etc/opendkim/SigningTable
-----
*@mydomain.com mail123456._domainkey.mydomain.com
-----

  vi /etc/opendkim/InternalHosts
-----
127.0.0.1
localhost
121.170.221.42
119.196.53.221
10.10.10.0/24
-----
  chown -R opendkim:opendkim /etc/opendkim

3. 재시작
  systemctl restart opendkim
  systemctl restart postfix

4. 테스트
  opendkim -n -x /etc/opendkim.conf
  opendkim-testkey -d mydomain.com -s mail123456 -vvv

위로 스크롤