Electronic Mail

By Pauline M. Berry

Electronic mail, or e-mail allows a user to send a message to an individual or group of individuals, it also allows the user to receive, read and store messages which arrive from other users. The mail program simply recognses incoming trafic as mail and translates it into a format compatible with the client system and forwards it to the correct recipient. Internet electronic mail is inherently more reliable than other mail delivery services. Internel mail operates by having the sender's machine contact the receiver's machine directly instead of using intermediate machines. Many networks have access to the Internet via e-mail without having full IP connectivity. They may need to explicitly address a gateway machine.

In very basic terms an e-mail message is broken down into two portions: the header and the body. These two portions are separated by an empty line. The header lists the sender, the recipient(s), the posting date and the subject field. The body contains the message.

When addressing mail from the Internet to another user on the Internet, the form user@host is used where the user is the name of the users mail account and the host is the FQDN of the host or of the host relaying mail to the user's host. As I said many hosts on other networks can e-mail to the Internet so a variety of address formats may be seen:

user@host
The @ sign is the most commonly used separator. Internet and Janet are examples of networks using this format.
host::user
This is prevalent in DEC networks.
host!user
This is called "bang syntax". It is used with UUCP mail. It allows source routing e.g.
host1!host2!user
Different UCP hosts are sepatated by the exclamation marks to indicate routing requirements
user%host1@host2
Allows source routing from the Internet. The user can specify a mail gateway (host2).
Electronic mail is a powerful tool and should be used with care. There is a basic etiquette which users have a duty to follow. Online mail tends to change a person's style of comminication, people generally become more direct and should be careful not to offend. Here are some basic guidelines:
  1. keep paragraphs and messages short
  2. focus on one subject per message
  3. include your signature at the end of messages (name, affiliation, internet address)
  4. don't forward personal e-mail without gaining author's permission
  5. respect copyright and license agreements
  6. follow the normal chain of command procedures (don't complain to the top)
Back To:
FULL COURSE INDEX | PAULINE BERRY | DIS | STRATHCLYDE UNIVERSITY

Last modified .