Configuring localhost to send messages fedora 26

Installing the required packages

sudo dnf install sendmail sendmail-cf

Editing sendmail.mc file

sudo vi /etc/mail/sendmail.mc

grep LOCAL_DOMAIN /etc/mail/sendmail.mc
LOCAL_DOMAIN(`server.sand.box')dnl

grep DAEMON_OPTIONS /etc/mail/sendmail.mc
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

Update sendmail configuration

sudo make -C /etc/mail

Restart and enable the service

sudo systemctl enable sendmail

Sending test mail.

mail -v user@example.com
Subject: test
test
.
EOT