Sendmail 설치 문제(sendmail-bin ERROR 및 locale warning) 도와주세요ㅜㅜ

안녕하세요.
서버에 sendmail 프로그램을 설치해서 SMTP를 구성하려고하는데..
sendmail를 설치하는 과정에서 계속 문제를 격고 있습니다 ㅜㅜ
일단.. OS는 데비안을 쓰는데요.. 서버를 설치하고 아직 라이브러리들이 다 안깔려서 그런지..
locale warning이 뜨면서 default로 set up할수 없다는 문구가 계속 뜨구요
또 sendmail 설치하는 과정에서
-----------------------------------------------------------------------------------
dpkg: error processing sendmail-bin (--configure):
subprocess installed post-installation script returned error exit status 100
dpkg: dependency problems prevent configuration of sensible-mda:
sensible-mda depends on sendmail-bin | mail-transport-agent; however:
Package sendmail-bin is not configured yet.
Package mail-transport-agent is not installed.
Package sendmail-bin which provides mail-transport-agent is not configured yet.
Package exim4-daemon-light which provides mail-transport-agent is not installed.
------------------------------------------------------------------------------------
이런식으로 에러가 발생해서.. 구글링을 해봐도 ㅠㅠ 어떻게 해결해서 sendmail를 설치
해야할지 잘모르겠습니다.....

----------------(설치 마지막 부분 메세지..)--------------------
Checking {sendmail,submit}.mc and related databases...
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/databases...
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/databases...
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/Makefile...
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Writing configuration to /etc/mail/sendmail.conf.
Writing /etc/cron.d/sendmail.
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
Disabling HOST statistics file(/var/lib/sendmail/host_status).
Creating /etc/mail/sendmail.cf...
Creating /etc/mail/submit.cf...
Informational: confCR_FILE file empty: /etc/mail/relay-domains
Informational: confCT_FILE file empty: /etc/mail/trusted-users
Updating /etc/mail/access...
Updating /etc/mail/aliases...
WARNING: local host name (watercooler) is not qualified; see cf/README: WHO AM I?
/etc/mail/aliases: 12 aliases, longest 10 bytes, 134 bytes total
invoke-rc.d: unknown initscript, /etc/init.d/sendmail not found.
dpkg: error processing sendmail-bin (--configure):
subprocess installed post-installation script returned error exit status 100
dpkg: dependency problems prevent configuration of sensible-mda:
sensible-mda depends on sendmail-bin | mail-transport-agent; however:
Package sendmail-bin is not configured yet.
Package mail-transport-agent is not installed.
Package sendmail-bin which provides mail-transport-agent is not configured yet.
Package exim4-daemon-light which provides mail-transport-agent is not installed.
dpkg: error processing sensible-mda (--configure):
dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of sendmail:
sendmail depends on sendmail-bin; however:
Package sendmail-bin is not configured yet.
sendmail depends on sensible-mda; however:
Package sensible-mda is not configured yet.
dpkg: error processing sendmail (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
sendmail-bin
sensible-mda
sendmail
E: Sub-process /usr/bin/dpkg returned an error code (1)
abc@watercooler:~$
-----------------------------------------------------------------

메세지가 긴것같지만.. 윗부분은 로케일이 계속 잘안됀다는것 같고..
밑에는 결국 exit state 100으로 sendmail-bin을 설치하는 과정에서 오류가 발생하는것을 볼수 잇는데요..
그래서 결국 sendmail이 설치 안됐다.. 이러는것 같습니다..
도와주세요. ㅜㅜ