postfix is Ubuntu’s default mail transfer agent (MTA) and can be configured to deliver mail using a relay host that requires SMTP authentication.
Get the necessary packages with the following command:
user@ubuntu:~$ sudo apt-get install postfix bsd-mailx
Begin to configure your postfix installation by choosing satellite system as the general type of configuration. Enter the local machine name as the mail name (eg mycomputer.edafe.org) and the SMTP server address of your email service provider as the SMTP relay host (eg smtp.relayhost.com).
Edit the file /etc/postfix/main.cf and add the following:
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options =
relay_domains =
Create the file /etc/postfix/sasl_passwd and make the following entries:
smtp.relayhost.com user:password
Substitute smtp.relayhost.com with the address of the SMTP relay host and user:password with your login details.
Continue by executing the following three commands:
user@ubuntu:~$ sudo chown root.root /etc/postfix/sasl_passwd
user@ubuntu:~$ sudo chmod 600 /etc/postfix/sasl_passwd
user@ubuntu:~$ sudo postmap hash:/etc/postfix/sasl_passwd
Instruct postfix to reload its settings with the following command:
user@ubuntu:~$ sudo /etc/init.d/postfix reload
Making changes to the alias table
The aliases table provides a system-wide mechanism to redirect mail for local recipients.
Edit the file /etc/aliases to contain the following entries:
postmaster: root
root: user@yourdomain.com
Substitute user@yourdomain.com with the email address that you would like mail for the root user to be redirected to.
Finally, update /etc/aliases.db using the following command:
user@ubuntu:~$ sudo newaliases
Mail for the local root user from now on will automatically be forwarded to user@yourdomain.com , using smtp.relayhost.com as the relay host.
www.postfix.org, help.ubuntu.com