Anatomy of an Email address

General format

Although there are some conventions, there are no specific rules about the format of an email address. An email address usually consists of 4 elements.

name@company.organization code

The fourth element, "location", is usually omitted for sites in the United States.

Here is an example of an email address for someone in the United States: (United States is implied)

Here is an example of an email address for someone outside the United States: (ca = Canada)


"Name" is the name of the person or position to whom you are sending the email. The name always appears before the @ [at] symbol.

If you have an email address through your organization, you may be subject to the organization's rules for establishing your name. Most ISPs allow you to choose anything you want for an email name. Sometimes, if you choose a popular name or belong to a giant provider like America Online, the name you want might already be in use and you will have to choose another.

Here are some examples of email names:


Company is a unique designation for the computer storing the addressee's email. This is usually the name of the organization which owns the machine.

Here are some examples of machine names:

Organization code [top-level domain name]

Organization code [also called "top-level domain name"] is a three letter code which designates the type of organization that operates the computer where the the addressee's email is stored.

Here are some examples of organization codes:

For a more complete list, click here.

Country Code

Location is a code used to designate the country where the computer and organization are located. Many addresses in the US do not include a location symbol, but some do. To make matters more confusing, some US government addresses include both a state and country symbol. Addresses in other countries always include a country code.

Note: You can tell that the example addresses we have been using in this presentation are in the US because there is no location symbol.

For a list of country codes, click here.