Goal
Introduce how Email is implemented in current Internet and related tech-skills.
Overview
Email Client
When a user wants to send/receive the email to/from a Email, he has to use the Email Cleint to interact with Email Server.
SMTP Server
SMTP is a protocol to transfer Email information.
For example, when a Email Client wants to send a Email to the Email Server, or a Email Server(@qq.com, etc.) want to send Email to another Email Server(@163.com, etc.)
IMAP/POP3
SMTP is responsible for sending email while IMAP/POP3 is responsbile for fetching Email.
Email Server builds a IMAP/POP3 Server to store emails, then the user can use the Email Client to access IMAP/POP3 Server to fetch Emails.