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Lesson 8

Internet Email Conclusion

Most computer users can't go a day without email. It is a powerful and pervasive medium that can make or break a business. Email is capable of bringing the world to your doorstep, but only if the infrastructure supporting it works.
In this module, you learned about the Internet's email architecture. You learned that Mail User Agents (MUAs) help the user compose and send email to Mail Delivery Agents (MDAs). The MDAs in turn decide where the email needs to go, usually up to a Mail Transfer Agent (MTA). The MTA inspects the message and decides where to send the message so that it will reach its intended destination.
You also learned about SPAM and the problems it causes to email systems. You explored tools to help combat the SPAM problem and to tackle spammers head-on.

Learning objectives

Having completed this module, you should now be able to:
  1. Explain how the Internet transfers email
  2. Define the roles of the three email system agents
  3. Describe the purpose of Linux's MTAs and MDAs
  4. Describe the purpose of Linux's MUAs
  5. Identify the traits of email SPAM
  6. List tools that combat email SPAM

Glossary terms

The following terms were introduced in this module:
  1. Agent: A program in the email system that inspects an email and decides how to move it further toward the ultimate destination.
  2. Blacklist: A list of known email abusers, such as spammers.
  3. Extended Simple Mail Transfer Protocol (ESMTP): An extension of SMTP, ESMTP is a ubiquitous protocol for email transfer.
  4. Fully-Qualified Domain Names (FQDN): A domain name that has all required DNS information: the host, network, and top-level domain.
  5. Internet Message Access Protocol (IMAP): A standard protocol for accessing mail from your local MDA.
  6. Mail Delivery Agents (MDA): The email agents responsible for local network email delivery.
  7. Mail Exchanger (MX): A special host designated to handle all the network's email.
  8. Mail Transfer Agents (MTA): The email agents responsible for Internet-wide email delivery Mail Transfer Agent (MTA)
  9. Mail User Agents (MUA): Programs responsible for displaying and composing email.
  10. Mail Abuse Prevention System (MAPS): A nonprofit organization dedicated to defending the Internet\'s email system from abuse.
  11. Real-time Blackhole List (RBL): A system designed to block sites known for spamming.
  12. MX records: Records in the DNS that describe which host handles mail for a given domain.
  13. POP3: An acronym for Post Office Protocol, version 3, POP3 is an older protocol that enabled MUAs to send and receive mail from MDAs.
  14. Recipes: A concise set of procmail instructions that filter or otherwise manipulate an email.
  15. Simple Mail Transfer Protocol (SMTP): The Internet\'s fundamental mail transfer protocol.
  16. SPAM: A common name for unsolicited email, named after a Monty Python sketch.
  17. Spammer: Anyone who sends SPAM.

The next module explains how to configure procmail.

Linux Email - Quiz

Before you move to the next module, click the Quiz button to check your understanding of email concepts.
Linux Email - Quiz