Send Emails from Linux with Postfix

This is for configuring Linux to be able to send emails.

This information was obtained from here for my enjoyment and so I don't have to look for this again. . This has been tested on a Raspbery pi and an Ubuntu machine.

This configuration uses Gmail as the email carrier. It will work with others, just used gmail in this configuration. Less secure apps or 2 factor with app passwords needs to be enabled for this configuration to work.

Install needed apps

sudo apt-get install postfix libsasl2-modules mailutils -y

Select internet site on installation

Add email password

sudo nano -B /etc/postfix/sasl/sasl_passwd

Add smtp.gmail.com:587 username@gmail.com:password with the appropriate information

Crtl+X' and Enter` to save and exit

Update the password file

sudo chmod u=rw,go= /etc/postfix/sasl/sasl_passwd
sudo postmap /etc/postfix/sasl/sasl_passwd

Edit postfix configuration file

sudo cp /etc/postfix/main.cf !#$.dist
sudo nano /etc/postfix/main.cf

Change relayhost = to relayhost = smtp.gmail.com:587

Change smtp_tls_security_level=may to #smtp_tls_security_level=may

Add this at the bottom

# Enable authentication using SASL.
smtp_sasl_auth_enable = yes
# Use transport layer security (TLS) encryption.
smtp_tls_security_level = encrypt
# Do not allow anonymous authentication.
smtp_sasl_security_options = noanonymous
# Specify where to find the login information.
smtp_sasl_password_maps = hash:/etc/postfix/sasl/sasl_passwd
# Where to find the certificate authority (CA) certificates.
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

Exit and Save with Ctrl+X and Enter

Restart Postfix

sudo service postfix restart

Send a test email

echo "Subject: Test Email Subject" | mail -a test_email@address.com < echo "Here is a test email"