Please note: this tutorial assumes postgres is already setup and configured on the machine.
Install & configure the dovecot and postfix:
apt-get install dovecot-core dovecot-pgsql postfix -y
Provision the smtp database in postgres:
su -c "psql -c \"CREATE USER smtp WITH PASSWORD 'smtp';\"" postgres su -c "psql -c \"CREATE DATABASE smtp WITH OWNER=smtp;\"" postgres
Encrypt you password using doveadm tool and SHA512-CRYPT:
doveadm pw -s SHA512-CRYPT -p test1234 -r 100000 ************************
Create the SQL file with your one test user:
cat > smtp.sql<<EOT
CREATE TABLE users (
id SERIAL,
username VARCHAR(128) NOT NULL,
password VARCHAR(512) NOT NULL,
constraint username_key unique (username)
);
insert into users (username, password) values ('emailuser01', '************************');
EOT
Import your SQL table and test user:
psql -h localhost -d 'smtp' -U smtp -W < smtp.sql
Configure dovecot
Open /etc/dovecot/conf.d/10-master.conf in your favorite text editor and uncomment the following:
# Postfix smtp-auth
unix_listener /var/spool/postfix/private/auth {
mode = 0666
}
Enable SQL and login auth:
sed -i "s/auth_mechanisms = plain/auth_mechanisms = plain login/g" /etc/dovecot/conf.d/10-auth.conf sed -i "s/\!include auth-system.conf.ext/#\!include auth-system.conf.ext/g" /etc/dovecot/conf.d/10-auth.conf sed -i "s/#\!include auth-sql.conf.ext/\!include auth-sql.conf.ext/g" /etc/dovecot/conf.d/10-auth.conf
Disable the default password scheme
sed -i "s/default_pass_scheme/#default_pass_scheme/g" /etc/dovecot/dovecot-sql.conf.ext
Enable SHA512-CRYPT and set database parameters
cat >>/etc/dovecot/dovecot-sql.conf.ext<<EOT default_pass_scheme = SHA512-CRYPT driver = pgsql connect = host=localhost dbname=smtp user=smtp password='smtp' password_query = select username as user, password from users where username = '%n'; EOT
Restart dovecot
service dovecot restart
Configure postfix to use dovecot for sasl
postconf -e 'smtpd_sasl_type = dovecot' postconf -e 'smtpd_sasl_auth_enable = yes' postconf -e 'smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination' postconf -e 'smtpd_sasl_path = private/auth'
Enable submission for clients on port tcp/587
sed -i "s/\#submission/submission/g" /etc/postfix/master.cf
Restart postfix
service postfix restart
Email client setup example
Now configure your mail client to use the SMTP server. For this example we will say the mail client is postfix and the smtp server we just setup has an IP of 192.168.0.186
192.168.0.186:587 emailuser01:test1234 > /etc/postfix/sasl_passwd
postmap hash:/etc/postfix/sasl_passwd
cat >>/etc/postfix/main.cf <<EOT smtp_sasl_auth_enable = yes smtp_sasl_mechanism_filter = plain, login smtp_sasl_security_options = noanonymous smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd relayhost = 192.168.0.186:587 EOT
Restart postfix
service postfix restart
Send test email
echo "TEST" > testemail mail -s "TEST EMAIL" me@myemaildomain.com < testemail