Structure of EMail

An email message comprises binary data, usually in the ASCII text format. ASCII is a standard that enables any computer, regardless of its system or hardware, to read the text. ASCII code describes the characters you see on your computer screen.

you can attach pictures, executable programs, sound, video, and other binary files to your email.

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consider the above sample email message with the postal mail message. In the To line, you type in the email address of the person to whom you are sending a message. The address must be typed according to a set of very strict rules. if you type a single letter or the syntax is wrong your message will not get to the intended recipient. your email address will appear on the Form line. using this address, the recipient of your message will be able to respond to you.

On the subject line, you may type in the subject of your message or a very brief summary. at the bottom of the message is a signature area that can contain personalized information about you. some mail programs will automatically append this signature to the bottom of every message you send. Signature areas are not required and are used at the discretion of the person who creates the email message. the signature portion should not exceed five lines. There are five sections of an email message:

1. E-mail address
2. header
3. body
4. signature (optional)
5. attachment (optional)

Email addressing system

It is important to understand and follow the email addressing scheme for the internet to ensure the proper delivery of all outgoing messages.

Address Syntax

An email address is composed of two separate parts.

1. the domain name of the mail server computer on which you have an email account.
2. your personal identity or account name (user name) on that mail server.

For example, 100 people have email accounts with the same ISP or organizations. All 100 users will share the same domain name (say hotmail.com), but each person will possess a unique user name, such as ‘Rahul’ or ‘Yash’. the user and domain names are separated by an @ (‘at’) symbol. Together, they form a complete email address.

The above image shows the components of an email address. users with multiple email accounts perhaps with different ISPs or organizations will have a different email address for each account.

Header

The header of the email message is the uppermost section. it displays information regarding the status of the messages. a header records message information and provides it to the recipient(s) of the message. headers are present in both outgoing (sent) and incoming (received) messages.

The principal header fields related to messages transported are listed below. these are mandatory to be used by all the people using email facilities on the internet. these areas power RFC 822.

1. To – Email address/addresses of the primary recipient(s).
2. Cc – Email address/addresses of the secondary recipient (s) to who copy needs to be sent.
3. Bcc – Email address/addresses of the secondary recipient (s) to whom copy needs to be sent but the primary recipient should not know about the despatch of mail to these addresses.
4. From – The originator of the creators of the email.
5. Sender – Email address of the actual sender.
6. Received – Line added by each transfer agent along the route containing the agent’s identity, and the date and time the message was received.
7. Return Path – This May be used to identify the path back of the sender.

Note that there is no space in the email address, software and server computers will not accept spaces in an address. messages will not reach their destination if spaces are included.

There are additional headers given in RFC 822, which are not mandatory but may be used if required.

1. Date – Date and time the message was sent.
2. Reply-to – Email address to which replies should be sent.
3. In-Reply-to – Message identification number of the message to which this is a reply.
4. Message-ID – A unique number identifying the message and may be used to refer to the message.
5. References – Other relevant message identification numbers.
6. Keywords – Keywords selected by the user.
7. Subject – A summary of the message for the one-line display.

The header shows information such as:

1. time and date of a message,
2. the subject of a message (as typed by the sender),
3. whether carbon copies were sent,
4. whether files are attached to the message, and
5. the email address of the sender.

Body

The body of the email message is the primary focus because it contains the actual message. although there is no limit to the size (number of characters) of an email message, many Internet Service Providers do limit the size of an email message.

Attachments

An email has become all the more attractive to businesses because now it allows users to attach a file to any email message. Any file format such as word processing documents, spreadsheets, images, or video files can be attached to an email message. email allows complex data as attachments but not in the body.

Email messages cannot viruses, but they can still be sent through attachments. Therefore, you should scan all email attachments with a virus detection and eradication software program such as McAfee VirusScan or Norton AntiVirus before opening, or forwarding them.

Most email applications alert you if an incoming message contains an attachment. Such email applications show an icon within the body of the messages to represent an attached file. the icon indicates the type of file that is attached and allows the recipient to double-click the icon to automatically launch the attachment on their computer.

Signature

The signature for an email message is the personal information that automatically appears at the bottom of the outgoing message. The use of a signature is optional. you can provide any signature information you wish.

The purpose of a signature (also called a signature block, or signature file) is to provide a message recipient with personal contact information.

Information in a signature block may include the following:

1. full name
2. job title/position
3. organization name and division
4. phone and fax numbers
5. physical and fax numbers
6. physical (snail mail) address
7. email address
8. Website address (URL)

By utilizing the signature features of the email software, you can avoid typing information for each outgoing message.

Carbon Copy (CC)

This feature lets you send a copy. carbon copy of the mail to another recipient. In this case, the main recipient is informed about the other people who receive the same message.

A signature allows information in this part to be included with each outgoing message in an automated and time-saving manner for the message sender.

Blind Carbon Copy (BCC)

In this option, the recipient does not know the name of the other recipients.