37 lines
2.4 KiB
Markdown
37 lines
2.4 KiB
Markdown
---
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obj: concept
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wiki: https://en.wikipedia.org/wiki/Email
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---
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# eMail
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Email, short for electronic mail, is a widely used method of exchanging digital messages over the Internet. It has become an integral part of personal and business communication, enabling the rapid and efficient exchange of information.
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## Key Components
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### 1. **Email Address:**
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- An email address uniquely identifies an individual or entity in the email system. It typically consists of a local part (username) and a [domain](Domain.md) part (e.g., username@example.com).
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### 2. **Mail User Agent (MUA):**
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- The Mail User Agent is an email client or application used by individuals to compose, send, receive, and manage emails. Examples include Outlook, [Thunderbird](../applications/communication/Thunderbird.md), and [Gmail](../applications/communication/Gmail.md).
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### 3. **Mail Transfer Agent (MTA):**
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- The Mail Transfer Agent is responsible for routing and transferring emails between servers. Common MTAs include Sendmail, Postfix, and Microsoft Exchange.
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### 4. **Mail Delivery Agent (MDA):**
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- The Mail Delivery Agent stores incoming emails in the recipient's mailbox. Examples include Dovecot and Courier.
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### 5. **Protocols:**
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- **[SMTP](SMTP.md) (Simple Mail Transfer Protocol):** Used for sending and relaying emails between servers.
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- **POP3 (Post Office Protocol 3):** Retrieves emails from a server and typically deletes them from the server after retrieval.
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- **IMAP (Internet Message Access Protocol):** Allows users to access and manage emails on the server, supporting multiple devices.
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### 6. **Email Headers:**
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- Email headers contain metadata about the message, including sender, recipient, subject, date, and other routing information.
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### 7. **Attachments:**
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- Emails can include attachments, such as documents, images, or other files, which are transmitted along with the message.
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## Email Workflow
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1. **Composition:**
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- The sender uses an MUA to compose an email, addressing it to one or more recipients.
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2. **Sending:**
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- The MUA uses [SMTP](SMTP.md) to send the email to the recipient's email server (MTA).
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3. **Routing:**
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- The recipient's MTA receives the email, checks the recipient's address, and relays it to the appropriate MDA.
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4. **Delivery:**
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- The MDA stores the email in the recipient's mailbox, making it accessible for retrieval.
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5. **Retrieval:**
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- The recipient's MUA retrieves emails from the server using POP3 or IMAP.
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