Installing OpenSMTPD on Ubuntu Server Latest

Step 1: Update System Packages

The first thing to do is to update your Ubuntu system.

$ sudo apt-get update
$ sudo apt-get upgrade

Step 2: Install OpenSMTPD

To install OpenSMTPD, we need to first add the OpenSMTPD package repository to the system. Run the following commands to add the repository:

$ sudo apt-get install -y wget
$ echo "deb http://www.opensmtpd.org/cgi-bin/cvsweb.cgi/~checkout~/OpenBSD/src/usr.sbin/smtpd/ smtpd/" | sudo tee -a /etc/apt/sources.list.d/opensmtpd.list
$ wget -O- https://opensmtpd.org/archives/opensmtpd.gpg.clustered | sudo apt-key add -
$ sudo apt-get update

Next, run the following command to install OpenSMTPD:

$ sudo apt-get install opensmtpd

Step 3: Configure OpenSMTPD

After installation, we will configure OpenSMTPD.

First, open the OpenSMTPD configuration file:

$ sudo nano /etc/smtpd/smtpd.conf

The configuration file will look something like this:

# Sample smtpd.conf(5) file.
#
# To enable this configuration file remove the .sample extension.

pki mycerts {
    certificate "/etc/ssl/private/mycert.pem"
    key         "/etc/ssl/private/mykey.pem"
}

table aliases {
    root:   postmaster
}

listen on all tls pki mycerts
auth-optional
accept from any for domain <mydomain.com> virtual <mydomain.com> \
    alias <aliases> deliver to mbox

Replace <mydomain.com> with your own domain name.

Next, add the following line to the end of the configuration file:

deliver to maildir "/var/mail/%{dest.domain}/%{dest.user}"

This will configure OpenSMTPD to use Maildir as its mail delivery method.

Finally, restart OpenSMTPD for the changes to take effect:

$ sudo systemctl restart smtpd

Step 4: Test OpenSMTPD

To test OpenSMTPD, create a test email:

$ echo "Test email body" | mail -s "Test email subject" [email protected]

Replace [email protected] with your own email address.

Check the mail log to see if the email was delivered successfully:

$ sudo less /var/log/mail.log

You should see a log entry that looks something like this:

smtpd[1234]: <example.com> from=<[email protected]> to=<[email protected]> ...

Congratulations! OpenSMTPD is now installed and configured on your Ubuntu server.