OpenSMTPD Howto (2)
Installation
Update the system:
sudo dnf updateinfo
sudo dnf -y upgrade
Install the required packages:
sudo dnf -y install 'opensmtpd'
Define OpenSMTPD as default mail daemon
sudo alternatives --set 'mta' '/usr/sbin/sendmail.opensmtpd'
sudo alternatives --display 'mta'
Configuration
Edit the configuration file:
Create a Google App Password.
Create file with the credentials:
cd '/etc/opensmtpd'
for file in 'secrets' 'secrets.db'; do
sudo install --group='smtpd' --mode=0640 '/dev/null' "${file}"
done
sudo echo 'gmail alex.the.lion@gmail.com:**********' >>'secrets'
sudo makemap 'secrets'
Validate the configuration:
sudo smtpd -n
Start the service & get its status:
sudo systemctl start 'opensmtpd.service'
sudo systemctl status 'opensmtpd.service'
Observe its logs:
sudo journalctl --unit='opensmtpd.service' --since 'today' --follow
Enable the service & check it:
sudo systemctl enable 'opensmtpd.service'
sudo systemctl list-unit-files | grep 'opensmtpd.service'
Test
- Observe its open ports
sudo lsof -a -c 'smtpd' -i -n -P
Output:
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
smtpd 55503 smtpd 10u IPv4 183344 0t0 TCP 127.0.0.1:25 (LISTEN)
smtpd 55503 smtpd 11u IPv4 183345 0t0 TCP 10.88.0.1:25 (LISTEN)
- Send a test email
sendmail -t -v
Content:
To: root
Subject: Test OpenSMTPD
This an OpenSMTPD test!