What is mail server ?

A mail server (also called an email server) is a computer system or software that sends, receives, and stores email messages.

It works like a digital post office — handling the delivery of messages between users on the same network or across the internet.

Here’s a breakdown of how it works 👇

📨 1. Types of Mail Servers

There are typically two main types:

• Outgoing Mail Server (SMTP Server)

  • Uses the SMTP protocol (Simple Mail Transfer Protocol).

  • Responsible for sending emails from your email client (like Outlook, Gmail, or Thunderbird) to other mail servers.

• Incoming Mail Server (POP3 or IMAP Server)

  • Uses POP3 (Post Office Protocol v3) or IMAP (Internet Message Access Protocol).

  • Responsible for receiving and storing emails, so users can read them.

  • POP3 downloads emails to your device, while IMAP keeps them on the server and syncs across multiple devices.

⚙️ 2. How Email Delivery Works

1. You write an email and click Send.

2. The SMTP server sends it to the recipient’s mail server.

3. The recipient’s incoming mail server (IMAP/POP3) receives it.

4. The recipient’s email client fetches and displays it.

📦 3. Examples of Mail Servers

• Google Gmail: smtp.gmail.com (SMTP), imap.gmail.com (IMAP)

• Microsoft Outlook: smtp.office365.com (SMTP), outlook.office365.com (IMAP)

• Self-hosted: Postfix, Exim, Dovecot, or Microsoft Exchange Server

🔐 4. Security Features

Mail servers often include:

• TLS/SSL encryption for secure transmission

• Spam filters and virus scanners

• Authentication (username/password) to prevent unauthorized access