Exim4

good link: https://www.mail-tester.com/

DKIM_CANON = relaxed
DKIM_SELECTOR = XXXXXXX
 
DKIM_DOMAIN = ${lc:${domain:$h_from:}}
DKIM_FILE = /etc/exim4/dkim/${dkim_domain}-private.pem
DKIM_PRIVATE_KEY=${if exists{/etc/exim4/dkim/${dkim_domain}-private.pem} {/etc/exim4/dkim/${dkim_domain}-private.pem}}
 
REMOTE_SMTP_HELO_DATA = ${lc:${domain:$h_from:}}
MAIN_TRUSTED_USERS = mail:www-data
MAIN_TLS_TRY_VERIFY_HOSTS =

# remove all emails
exim -bp | awk '/^ *[0-9]+[mhd]/{print "exim -Mrm " $3}' | bash
# or 
exim -qff

#Remove all mails
exim -bp | exiqgrep -i | xargs exim -Mrm


  5  exim -bp
    6  exim -bp | awk '/^ *[0-9]+[mhd]/{print "exim -Mrm " $3}' | bash
    7  tail -f /var/log/exim4/mainlog 
    8  ls
    9  vi update-exim4.conf.conf 
   10  ls /etc/mailhelo
   11   
   12  /usr/share/doc/exim4-base/examples/exim-gencert
   13  vi update-exim4.conf.conf 
   14  cd /etc/exim4
   15  openssl genrsa -out dkim.private.key 1024
   16  openssl rsa -in dkim.private.key -out dkim.public.key -pubout -outform PEM
   17  chmod 640 dkim.p*
   18  chown root:Debian-exim dkim.p*
   19  vi exim4.conf.template 
   20  update-exim4.conf
   21  ls
   22  vi update-exim4.conf.conf 
   23  vi exim4.conf.template 
   24  update-exim4.conf
   25  service exim4 restart
   26  cat /etc/exim4/dkim.public.key 
   27* 
   28  update-exim4.conf
   29  service exim4 restart
   30  tail -f /var/log/exim4/mainlog 
   31  history
   32  tail -f /var/log/exim4/mainlog 
   33  history