--- title: "Browser features; POP, SMTP, IMAP comparison" subject: "Internet and Intranet" chapter: 3 key: "semester_8/internet_and_intranet:pop-smtp-imap-compare" source: https://www.bctengineer.com/q/semester_8/internet_and_intranet/pop-smtp-imap-compare site: BCT Engineering --- # Browser features; POP, SMTP, IMAP comparison Internet and Intranet · Chapter 3: Protocols and Client/Server Applications - Asked in: 2074 Magh, 5+5 marks; 2072 Magh, 5+5 marks (asked 2 times) - Video: [Lec-85 : SMTP vs POP3 vs IMAP with real life example | All in 1 | Application layer Protocols](https://www.youtube.com/watch?v=cjPVlxmf_Vk) — Gate Smashers - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_8/internet_and_intranet/pop-smtp-imap-compare - Whole chapter: https://www.bctengineer.com/md/semester_8/internet_and_intranet/chapter-3 ## Question What are the features that a web browser need to incorporate? Compare and contrast among POP, SMTP and IMAP. ## Short answer A browser needs HTTP/HTTPS support, a rendering engine, JavaScript, navigation tools, cache/cookies, security, and extensions. SMTP is a push protocol for sending mail on ports 25/587; POP3 downloads and usually deletes mail from the server on port 110; IMAP keeps mail on the server with two-way sync on port 143. ## Answer #### Features a web browser needs to incorporate A **web browser** is client software that requests, retrieves and displays web content. It should include: 1. **Protocol support:** HTTP/HTTPS, and others such as FTP, mailto and file; HTTP/2 or HTTP/3. 2. **Address bar and URL handling:** loads a page from a URL and supports search. 3. **Rendering engine:** parses HTML, CSS and displays layout; supports images, fonts, audio and video. 4. **Scripting support:** a JavaScript engine and the DOM for dynamic pages and web apps. 5. **Navigation tools:** back/forward, refresh, tabs, bookmarks, history, home page. 6. **Cache and cookies:** stores pages and session data to load faster and keep user state. 7. **Security:** TLS/SSL certificate checks, pop-up and phishing protection, sandboxing, safe-browsing warnings, private mode. 8. **Plug-ins and extensions:** to add features such as ad blockers. 9. **Download manager** and printing. 10. **Developer tools,** accessibility, multi-language and cross-platform support, proxy settings. #### POP, SMTP and IMAP - **SMTP (Simple Mail Transfer Protocol):** a *push* protocol that sends mail from a client to its server and between mail servers (port 25, submission 587). It cannot fetch mail. - **POP3 (Post Office Protocol v3):** a *pull* protocol that downloads mail from the server to the client (port 110, secure 995). Mail is usually deleted from the server after download. - **IMAP (Internet Message Access Protocol):** a *pull* protocol that lets the client read and manage mail kept on the server (port 143, secure 993). ```text Sender --SMTP--> Sender server --SMTP--> Recipient server | POP3 / IMAP v Recipient ``` | Basis | SMTP | POP3 | IMAP | |---|---|---|---| | Purpose | Send/relay mail | Retrieve mail | Retrieve and manage mail | | Direction | Client to server, server to server | Server to client | Server to client, with two-way sync | | Storage | Not a storage protocol | Mail stored on the local device | Mail stays on the server | | Multiple devices | Not applicable | Poor; mail is on one device | Good; same view on all devices | | Folders | No | Only local folders | Server-side folders and flags | | Offline use | No | Good; whole mail is local | Limited unless cached | | Bandwidth | Moderate | Downloads everything once | Downloads headers first, body on demand | | Ports | 25, 587, 465 | 110, 995 | 143, 993 | ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is the role of SMTP? A. It pushes mail from client to server and between servers; it cannot fetch mail B. It downloads mail to the client C. It stores mail in server folders for multiple devices D. It encrypts web pages Answer: A. SMTP is a push protocol for sending and relaying mail; receiving needs POP3 or IMAP. (Key point: SMTP role) 2. How do POP3 and IMAP differ in where mail is kept? A. POP3 keeps mail on the server; IMAP downloads it and deletes it B. POP3 usually downloads mail to the local device; IMAP keeps mail on the server C. Both always delete mail from the server D. Both only send mail Answer: B. POP3 downloads and usually deletes from the server; IMAP leaves mail on the server so it can be managed there. (Key point: POP3 vs IMAP storage) 3. Which protocol suits a user reading the same mailbox on phone and laptop? A. POP3 B. SMTP C. IMAP D. FTP Answer: C. IMAP provides two-way sync with server-side folders and flags, giving the same view on all devices. (Key point: Multiple devices) 4. Which port pair is correct for secure POP3 and secure IMAP? A. 995 and 993 B. 110 and 143 C. 25 and 587 D. 993 and 995 Answer: A. Secure POP3 uses 995 and secure IMAP uses 993. (Key point: Port numbers) ## Related in Internet and Intranet - [Internet vs Intranet and DNS need](https://www.bctengineer.com/question.md?key=semester_8%2Finternet_and_intranet%3Ainternet-intranet-compare-dns) — Internet and Intranet, chapter 1 - [Intranet, Internet, Extranet comparison and resources](https://www.bctengineer.com/question.md?key=semester_8%2Finternet_and_intranet%3Aintranet-internet-extranet-compare) — Internet and Intranet, chapter 1 ## Related in other subjects - [Short note: SMTP and POP](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Asmtp-pop-note) — Computer Networks and Security, chapter 6 - [Compare POP3 and IMAP](https://www.bctengineer.com/question.md?key=semester_7%2Fcomputer_networks_and_security%3Apop3-vs-imap) — Computer Networks and Security, chapter 6 - [Web documents, browser, information retrieval](https://www.bctengineer.com/question.md?key=semester_7%2Fweb_technology%3Aweb-documents-browser-retrieval) — Web Technology, chapter 2 - [Compare and contrast pollution in a city](https://www.bctengineer.com/question.md?key=semester_5%2Fcommunication_english%3Acompare-contrast-pollution-city-nepal) — Communication English, chapter 1