Browser features; POP, SMTP, IMAP comparison

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).

 Sender --SMTP--> Sender server --SMTP--> Recipient server
                                              |
                                        POP3 / IMAP
                                              v
                                         Recipient