Unix sendmail Program (Conclusion)
In this module, you learned the basics of configuring, testing, and running the
Now that you have completed this module, you should be able to:
- Explain the email process and the use of agents
- List the major responsibilities of the
- Describe how
sendmail uses the SMTP protocol to forward email across the Internet
- Use a .mc template file and M4 to create a
sendmail configuration file automatically
- Test a new
sendmail configuration before deploying it
nslookup to view MX records
Describe the Unix sendmail Program
Sendmail is a mail transfer agent (MTA) that is used to send and receive email messages on Unix-like operating systems. It was one of the first MTAs to be developed and has been widely used for many years. Sendmail operates as a daemon, listening for incoming connections and processing messages as they are received. It can be configured to work with various types of mail servers and can handle a wide range of email protocols, including Simple Mail Transfer Protocol (SMTP), Post Office Protocol (POP), and Internet Message Access Protocol (IMAP).
Sendmail is a powerful and flexible program, but it can be difficult to configure and maintain, particularly for inexperienced users. It is not as user-friendly as some of the more modern MTAs that have been developed in recent years. Despite this, Sendmail is still widely used on many Unix-like systems, particularly on servers where it is important to have a robust and reliable MTA.
In this module, we used the following terms:
- aliasing: Aliasing allows all users to refer to users by simple nicknames or by names other than their UNIX user name
- M4: M4 is a macro language that works with sendmail and, among other things, greatly simplifies sendmail configuration.
- Mail Delivery Agent: A Mail Delivery Agent (MDA) copies the message from the Mail Transfer Agent (MTA) into the users mailbox file.
- Mail Exchange (MX) record: An MX record is a type of Resource Record that defines a mail exchange host.
- Mail Transfer Agent: A Mail Transfer Agent (MTA) is a program that routes email among different machines.
- Mail User Agent: A Mail User Agent (MUA) is a program that allows users to compose, send, receive, and access email messages
- masquerading: Masquerading is the ability for a sendmail daemon to rewrite a subdomain\'s email address.
- SMTP: Simple Mail Transport Protocol (SMTP) is an application layer protocol for routing email.
Using Configuring Sendmail - Quiz