Ubuntu: Forward System Email

If you want to forward system emails to a real email address:
Run all commands as sudo -i
Replace email@example.com with your destination email.

1. Install Sebndmail:
   sudo apt-get install sendmail
2. Make sure the last line of /etc/aliases is: root: email@example.com
   vi /etc/aliases
3. Get the hostname:
   hostname
4. Add the hostname to genericsdomain
   cd /etc/mail
   vi genericsdomain
5. Map your local user name to recipient email e.g.:
   vi genericstable
   [username]@[hostname] email@example.com
6. Add your username as a trusted user:
   vi trusted-users
   [username]
7. To prevent long DNS timeouts each time sendmail restarts or tries to send an email add "localhost.localdomain " to # localhost, for example:
   vi /etc/hosts
   127.0.0.1 localhost localhost.localdomain [hostname]
8. Edit sendmail to add before the line "MAILER_DEFINITIONS":
   vi sendmail.mc
   dnl #
   MASQUERADE_AS(`email@example.com')
   dnl FEATURE(`allmasquerade')
   dnl FEATURE(`masquerade_envelope')
   dnl # 
9. Rebuild and reload the sendmail config:
   sendmailconfig
   /etc/init.d/sendmail reload sendmailconfig 
10. Now you should be able to email yourself:
    apt install mailutils
    echo "test" | mail --debug-level=15 -s "test email" email@example.com