Computer Networks · Class 12 · Network Protocols · Email
networksprotocols⏱️ 5 min read
POP3
SMTP left Priya’s email waiting in Aman’s mailbox on a mail server. It is not on Aman’s phone yet. Getting it down to the phone is the job of a second email protocol.
1What POP3 is
POP3
POP3 stands for Post Office Protocol version 3 (often written Post Office Protocol 3). It is the protocol used for retrieving emails from a mail server: the mail app logs in to the mailbox and downloads the mail to the device.
Fetching the mail
Play the story, then try it with a copy left on the server. Drag sideways to turn.
2How POP3 works
- The mail app connects to the mail server and logs in with a user name and password.
- It downloads every email waiting in the mailbox onto the device.
- Usually, the emails are then deleted from the server. (Most apps can be set to leave a copy.)
- The mail is now on the device, so it can be read even with no internet.
3SMTP and POP3 together
| SMTP | POP3 | |
|---|---|---|
| Full form | Simple Mail Transfer Protocol | Post Office Protocol version 3 |
| Job | Sends email | Retrieves email |
| Direction | Pushes mail towards the receiver's mail server | Pulls mail from the mail server to your device |
| Post office picture | Posting the letter | Collecting it from your letter box |
Beyond the syllabus: IMAP
Many phone mail apps use IMAP instead of POP3. IMAP keeps the mail on the server and shows it on every device you use, where POP3 downloads it to one device. Only POP3 is in your syllabus.
4From the board papers
1
________ is a protocol used for retrieving emails from a mail server. a) SMTP b) FTP c) POP3 d) PPPCBSE sample paper 2025-26
1 mark▶Show the answer
c) POP3 — CBSE’s marking scheme answer.
2
Expand the term POP3.CBSE sample paper 2023-24 (with URL) · “POP” with TCP in the compartment exam 2025
1 mark▶Show the answer
Post Office Protocol 3 (version 3). If the question writes just POP, write Post Office Protocol.
5Check yourself
Quick Check
Aman's email app downloads three new emails onto the phone. Which protocol did that?
Quick Check
After POP3 downloads the mail with its usual setting, where is the mail?