먼저 , 답변 감사드립니다. 
그런데 Maillog 를 보다가 약간 이상한 부분이 있는것 같아서요, 분석 좀 부탁드려도
될까요?

1. Permission denied

Sep  1 10:52:05   sendmail[2991]: h811q1p02991: from=<administrator@itiscom.co.kr>,
size=42630, class=0, nrcpts=1, msgid=<5666186.1062381643484.JavaMail.root@www.itwarehouse.co.kr>,
proto=SMTP, daemon=MTA, relay=ZZZZ[xxx.xxx.xxx.xxx]
Sep  1 10:52:06 XXXX sendmail[2992]: h811q1p02991: forward
/home/user1/.forward.XXXX: Permission denied
Sep  1 10:52:06 XXXX sendmail[2992]: h811q1p02991: forward /home/user1/.forward:
Permission denied

Sep  1 10:51:30 XXXX sendmail[2981]: h811pSp02981: from=<callcenter@mailer.pricengo.com>,
size=22763, class=0, nrcpts=1, msgid=<1427.43292.8617.1062381626@callcenter@mailer.pricengo.com>,
proto=SMTP, daemon=MTA, relay=ZZZZ[xxx.xxx.xxx.xxx]
Sep  1 10:51:30 XXXX sendmail[2982]: h811pSp02981: forward
/home/user2/.forward.XXXX: Permission denied
Sep  1 10:51:30 XXXX sendmail[2982]: h811pSp02981: forward /home/user2/.forward:
Permission denied
Sep  1 10:51:30 XXXX sendmail[2982]: h811pSp02981: to=<user2@AAAA>,
delay=00:00:01, xdelay=00:00:00, mailer=local, pri=52042, dsn=2.0.0, stat=Sent

 : User1, User2 라는 계정은 현재 존재하는 계정입니다. 


2. NOQUEUE 
  
Sep  1 10:51:27 XXXX sendmail[2946]: NOQUEUE: [xxx.xxx.xxx.xxx] did not issue
MAIL/EXPN/VRFY/ETRN during connection to MTA  
Sep  1 10:52:59 XXXX sendmail[2997]: NOQUEUE: [xxx.xxx.xxx.xxx] did not issue
MAIL/EXPN/VRFY/ETRN during connection to MTA