Network and Internet Fundamentals
Senior 1 · ICT
Network and Internet Fundamentals
Lesson 4 of 5
20 min
Chat apps are quick, but schools, universities, banks, employers and government offices still use email for anything official: admission letters, job applications, receipts and reports. Almost every online account, from a school learning platform to a scholarship application, asks for an email address. Knowing how to use email well is a skill you will need for the rest of your studies and working life.
Email (electronic mail) is a way of sending messages, with files attached if you wish, from one person's mailbox to another person's mailbox over the internet. The receiver does not need to be online when you send it: the message waits in their inbox until they open it.
You can use email in two ways: through webmail, which you open in a browser (for example Gmail or Outlook.com), or through an email app installed on your phone or computer.
Every email address has the same shape: username @ domain name, written without spaces.
keza.uwase): identifies the person's mailbox. It is chosen when the account is created.example.rw): the organisation or email provider that holds the mailbox.So the address means "the mailbox of keza.uwase at example.rw". No two people can have the same address.
| Address | Valid? | Reason |
|---|---|---|
mugisha.eric@example.rw | Yes | Username, one @, domain name |
mugisha eric@example.rw | No | Contains a space |
mugisha.eric.example.rw | No | No @ sign |
mugisha@@example.rw | No | Two @ signs |
@example.rw | No | No username |
Habimana receives this email:
From: Security Team <support@gmai1-security.example.com>
Subject: URGENT: your account will be closed today
Click this link and enter your password within 2 hours to keep your account.
Warning signs: the sender's domain is not the real provider (note the number 1 in place of the letter l); it creates panic ("URGENT", "2 hours"); and it asks for a password. A genuine provider never asks for your password by email. Habimana should delete it and not click the link.
Tip
Memory hook: an email address answers two questions, who @ where: the username is who, the domain name is where. Exactly one @, and never a space.
In the address habimana.jean@example.ac.rw, give the username and the domain name.
Solution: Username: habimana.jean. Domain name: example.ac.rw (the .ac.rw ending suggests a university or college in Rwanda).
Explain why ishimwe claude@example.rw is not a valid address.
Solution: It contains a space. Email addresses cannot contain spaces; a dot or underscore is used instead, as in ishimwe.claude@example.rw.
Give three advantages of email over sending a letter by post.
Solution: Any three of: it arrives in seconds; it costs only a little data; it can go to many people at once; files can be attached; a copy is kept and can be searched.
Your friend's email says: "Your school fees portal is locked. Reply with your password to unlock it." What should you do?
Solution: Do not reply and do not send the password: this is phishing. Your friend's account may have been hacked, so tell your friend by another route (a phone call, or in person) and report the email.
Summary
Sources and credits
The address diagram, the valid-or-not table, the phishing example and the practice items were written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
keza.uwase@example.rw
\________/ \________/
username domain name