华为电子邮件显示未读邮件1

什么是电子邮件或电子邮件？ (What Is Electronic mail or e-mail?)

Electronic mail or e-mail (from ‘electronic mail’) is an Internet service from which the user can send or receive messages. It is the Internet application most known and used today. Its creation dates back to 1972, when Ray Tomlinson installed on the ARPANET system able to exchange messages between different universities, but who is really defined the operation was Jon Postel.

电子邮件或电子邮件(来自“电子邮件”)是一种Internet服务，用户可以从中发送或接收消息。 它是当今最著名和使用的Internet应用程序。 它的创建可以追溯到1972年，当时，雷·汤姆林森(Ray Tomlinson)安装在ARPANET系统上，该系统能够在不同大学之间交换消息，但真正定义该操作的是Jon Postel。

It is the counterpart of digital and electronic mail and hard copy. Unlike the latter, the delay comes from the sender to the recipient is usually a few seconds / minutes, although there are exceptions which delay the service until a few hours.

它是数字和电子邮件以及纸质副本的副本。 与后者不同，从发送者到接收者的延迟通常为几秒/分钟，尽管有一些例外情况会将服务延迟到几小时。

Service model

服务模式

The aim of the e-mail message transfer from one user to another.

电子邮件从一个用户转移到另一个用户的目的。

Each user can have one or more mailboxes on which it receives messages that are stored. When desired, the user can see the contents of his box, organize, and send messages to one or more users.

每个用户可以具有一个或多个邮箱，在该邮箱上接收存储的消息。 需要时，用户可以查看其框内的内容，组织并将消息发送给一个或多个用户。

Access to the mail box is normally controlled by a password or other forms of authentication.

通常通过密码或其他形式的身份验证来控制对邮箱的访问。

How to access the service is therefore asynchronous, or for transmission of a message sender and recipient must be simultaneously active or connected.

因此，如何访问服务是异步的，或者对于消息的传输，发送方和接收方必须同时处于活动状态或已连接。

Delivery of messages sent to the recipient is not guaranteed. If an SMTP server fails to deliver a received message, normally try to send a notification to the sender to advise of non-delivery, but this notification is itself an e-mail (generated automatically by the server), and then his delivery is not guaranteed.

无法保证发送给收件人的邮件的传递。 如果SMTP服务器无法传递收到的邮件，通常尝试向发件人发送通知以告知未传递，但是此通知本身就是一封电子邮件(服务器自动生成)，因此他的传递不是保证。

The sender may also request a delivery or read the messages sent, but the recipient is usually able to decide if he wants to or not to send such confirmation. The meaning of the read receipt can be ambiguous, because you receive a message for a few seconds in a client does not mean having read, understood, or have shared the content.

发件人还可以请求发送邮件或阅读已发送的消息，但是收件人通常可以决定是否要发送此类确认。 已读回执的含义可能不明确，因为您在客户端中收到几秒钟的消息并不意味着已读，理解或共享内容。

电子邮件 (E-mail)

Each box is associated with one or more email addresses. These have the form username @ domain, where username is a name chosen by the user or administrator of the server, that uniquely identifies a user (or group of users), and domain is a DNS name.

每个框都与一个或多个电子邮件地址相关联。 它们的格式为username @ domain，其中username是服务器的用户或管理员选择的名称，用于唯一标识用户(或用户组)，domain是DNS名称。

The e-mail can contain any character alphabetical and numerical (excluding accents) and some symbols like the underscore (_) and dot (.). Very often can be useful to redirect users to use the services used to automatically forward all messages that arrive on the mailbox, to another of their choice, so that when the consultation must not access all the boxes e-mail available, but a check is sufficient.

电子邮件可以包含字母和数字的任何字符(不包括重音符号)以及一些符号，例如下划线(_)和点(。)。 在很多情况下，重定向用户以使用用于自动转发到达邮箱的所有邮件的服务到他们选择的另一个服务非常有用，这样在咨询时不能访问所有可用的邮箱，但要进行检查足够。

电子邮件系统架构 (System Architecture of e-mail)

The basic components of the system of e-mails are:

电子邮件系统的基本组成部分是：

• Clients (known in jargon MUA, Mail User Agent) used to access a mailbox and send messages用于访问邮箱和发送邮件的客户端(在术语MUA(邮件用户代理)中为已知)
• Servers, which serve two main functions:服务器，具有两个主要功能：
• or store messages for one or more users (known in jargon MS Message Store)或存储一个或多个用户的消息(在术语“ MS消息存储”中为人所知)
• or receive messages and incoming and outgoing channel it (called in the jargon MTA, Mail Transfer Agent).或接收邮件以及它的传入和传出通道(在术语MTA(邮件传输代理)中称为)。

The protocols typically used for exchanging emails are SMTP, used for sending, receiving and forwarding messages between servers, POP and IMAP, used for receiving messages and consultation by users.

通常用于交换电子邮件的协议是SMTP(用于在服务器之间发送，接收和转发消息)，POP和IMAP(用于接收消息和用户咨询)。

Clients require the configuration of the server to contact, and are therefore suitable mainly used computers regularly. It is also very common to consult a mailbox through the web.

客户端需要服务器的配置才能联系，因此经常成为适合使用的主要计算机。 通过网络查询邮箱也很常见。

电子邮件 (E-mail)

An e-mail consists of:

电子邮件包括：

• An envelope (envelope)信封(信封)
• A section header (header)节标题(header)
• A message body (body)邮件正文(正文)

The benchmark is the RFC, RFC 822, and RFC 2822 (he has made obsolete the previous year).

基准是RFC，RFC 822和RFC 2822(前一年已过时)。

Env

环保

For envelope is the information supplied with the message that is exchanged between servers via SMTP, mainly e-mail sender and recipients. This information normally corresponds to those that you can find in the headers, but it may be different.

信封是随邮件一起通过SMTP在服务器之间交换的信息所提供的信息，主要是电子邮件的发送者和接收者。 此信息通常对应于标题中的信息，但可能有所不同。

Headers

标头

Headers are information service used to control the sending of the message, or keep track of the manipulations affected. Each header consists of a line of text with a name followed by ‘:’ and the corresponding value.

标头是一种信息服务，用于控制消息的发送或跟踪受影响的操作。 每个标题均由一行文本组成，该文本行的名称后面带有“：”和相应的值。

Some of these are defined by the user. Among the main ones include:

其中一些由用户定义。 其中主要包括：

• Subject: (Subject:) should contain a brief description of the message. It is considered good manners to use this field to help the recipient understand the message content.主题：(主题：)应包含对消息的简短描述。 使用此字段来帮助收件人理解邮件内容是一种很好的方式。
• From: (From:) contains the e-mail address.发件人：(发件人：)包含电子邮件地址。
• To: (A) contains the email addresses of the main targets.收件人：(A)包含主要目标的电子邮件地址。
• Cc: contains the e-mail addresses in the carbon copy (carbon copy).抄送：在抄送副本(抄送副本)中包含电子邮件地址。
• Bcc (Bcc:) contains the e-mail addresses in copy hidden knowledge (blind carbon copy) or recipients who receive the message but whose address does not appear among the recipients. This is actually a pseudo-header, since it is only visible to the sender of the message, and by definition is not shown in messages sent to recipients.密件抄送(Bcc :)包含电子邮件副本中的隐藏知识(密件抄送)或接收邮件但其地址未出现在收件人中的收件人。 这实际上是一个伪标题，因为它仅对邮件的发件人可见，并且按照定义，在发送给收件人的邮件中没有显示。
• Reply-to: (Reply:) contains the e-mail address to which must be sent any replies to the message, if different from sender.回复：(Reply :)包含电子邮件的任何回复，如果与发件人不同，则必须将邮件的任何回复发送到该电子邮件地址。
• Date: (Date:) contains the date and time the message was written.日期：(Date :)包含写消息的日期和时间。

Headers of service

服务标题

Other headers are added by programs that manipulate the message.

其他标头由操纵消息的程序添加。

The most important is the Received: header which is added to each SMTP server handling the message, specifying which IP address the message was received, what time, and other useful information to trace the route.

最重要的是Received：标头，该标头添加到处理该邮件的每个SMTP服务器中，指定接收该邮件的IP地址，时间和跟踪路由的其他有用信息。

Other headers signal that the message was rated by some kind of antivirus or spam filter automatically, and the assessment made by the filter.

其他标头表示该邮件已被某种防病毒或垃圾邮件过滤器自动评估，并由该过滤器进行评估。

Message-ID: (ID of the message) is a code constructed by the client on which the message was composed, which are expected to uniquely identify a message.

消息ID ：(消息的ID)是由在其上组成消息的客户端构建的代码，可以预期该代码唯一地标识一条消息。

Continued…

继续…

翻译自: https://www.eukhost.com/blog/webhosting/electronic-mail-e-mail-part-1/

华为电子邮件显示未读邮件1