Sendmail as a send-only local server

• # cd /usr/share/sendmail/cf/cf
• Edit sendmail-slackware.mc :
  • Add the line FEATURE(`no_default_msa')dnl to the FEATURE block
  • Add the lines

DAEMON_OPTIONS(`NAME=NoMTA4, Family=inet, Addr=127.0.0.1')dnl DAEMON_OPTIONS(`Name=MSA4, Family=inet, Addr=127.0.0.1, Port=587, M=E')dnl right before the MAILER lines

• # m4 sendmail-slackware.mc > /etc/mail/sendmail.cf

• Add something like

root:           user
user:           user@example.org

to /etc/mail/aliases; then run the command newaliases

• # /etc/rc.d/rc.sendmail restart
• Make sure that the fqdn-hostname is in the DNS and is whitelisted in the inbound smtp server for example.org