Linux: Email - Paiet/Tech-Journal-for-Everything GitHub Wiki

Managing Email

  • Background
    • Installed by default on most distros
    • Used for system notifications (cron)
    • Message Transfer Agents (MTA)
      • Simple Mail Transfer Protocol (SMTP)
      • Used for sending email
      • Used for transfering email between servers
    • Mail User Agents (MUA)
      • Post Office Protocol (POP3)
      • Internet Message Access Protocol (IMAP4)
      • Used for receiving e-mail
  • MTAs
    • Qmail
      • High performance, but no longer directly updated
    • Postfix
      • Complex configuration but good balance of features and security
    • Sendmail
      • Stable and mature but a spotted security history
    • Exim
      • Very feature rich, but poor performance
    • Sendmail was popular for a long time
    • Postfix is the default for most distros now - SMTP on TCP/25
      • Emulates the 'sendmail' handling/calls to preserve functionality with older software
      • /etc/postfix/main.cf (Main configuration)

To Begin

myhostname = mail.example.com
mydomain = example.com
myorigin = $mydomain
inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
mynetworks = 192.168.0.0/24, 127.0.0.0/8
relay_domains = $mydestination
relayhost = [192.168.0.5]
home_mailbox = Mailbox
# Mailbox maps to /var/spool/mail/<username>

  • Next

    • Aliases can be defined in /etc/aliases
      • root: john
      • Delivers mail for root to John
      • Only root can edit /etc/aliases
      • Users can configure their own forwards by: + vi ~/.forward - user1 - user2 - user3
        • That will forward all of their e-mail to the three listed users.
      • Execute 'newaliases' to update

  • MUAs

Example

mail -s "Test email" dpezet
This is a test email.
.
⚠️ **GitHub.com Fallback** ⚠️