E-mail addresses typically have two main parts: the user name and the domain name.
Here's an example:
professor is the user name and refers to the recipient's mailbox. After the @ sign comes learnthenet, the host name, also called the domain name. This refers to the mail server, the computer where the recipient has an electronic mailbox. It's usually the name of a company or organization.
The end of the domain name consists of a dot (“.”) followed by three or more letters (such as .com and .gov) that indicate the top-level domain (TLD). This part of the domain name indicates the type of organization or the country where the host server is located. In the case of our example, the top level domain is .com.
There are many top-level domains in use on the web, and more top-level domains are made available on a regular basis. Here are some of the most common top-level domains currently in use:
- .aero–For the air-transport industry
- .biz–Reserved for businesses
- .com–For businesses and commercial enterprises; most companies use this extension
- .coop–Reserved for cooperatives
- .edu–For educational institutions and universities
- .gov–Reserved for United States government agencies
- .info–For informational sites
- .int–For organizations established by international treaties
- .jobs–For employment-related sites
- .mil–For the United States military
- .mobi–For sites related to mobile devices
- .museum–For use by museums
- .name–For use by individuals
- .net–For networks; usually reserved for organizations such as Internet service providers
- .org–For non-commercial organizations
- .pro–For use by licensed professionals, such as attorneys and physicians
- .tel–For services connecting phone networks and the Internet
- .travel–For travel-related services, like airlines, hotels and agents
More information about top-level domains is available at the website of ICANN, the organization that administers TLDs.
For e-mail addresses outside of the United States, there is often a two letter country code. For instance, .ca indicates Canada, .uk indicates the United Kingdom and .mx indicates Mexico. Here's a complete list of Internet country and territory codes.
E-mail Address vs. Web Address
Below you can see the difference between an e-mail address and the address of a website, also known as a URL. Notice that a Web address never contains an @ sign.
E-mail address: firstname.lastname@example.org
Web address: www.whitehouse.gov
For a fascinating history of the now ubiquitous @ sign, read “Where It's At.”
Frequently Asked Questions
How can I get an email address using a custom domain name and top-level domain?
If you want an email account that has a custom domain name and TLD you have a few options. First, you could register the domain name with a domain name registrar such as Domain.com or Namecheap, and elect to purchase email service from them as well. Second, you could work with an email provider such as Gmail and purchase a premium plan which includes support for custom domain names. Finally, if you already have a website hosted at the domain name you want to use for email, log into your hosting acount and look for email account settings in the hosting account control panel. Depending on the details of your hosting plan, you can probably create email addresses from your hosting account control panel and then follow their instructions for accessing the account using either a web-based email client or a desktop email application such as Microsoft Outlook.
What happens if I type in an email address incorrectly?
If you accidentally type in an email address incorrectly one of two things will happen. First, if the mistyped email address actually exists the email will be delivered to that email inbox. You can try to retract the email – a somewhat technical step that varies considerably from one email client to the next – but there's a good chance the email will simply be delivered to the address you typed. Second, if the mistyped email address doesn't exist you'll receive an error message stating that the email could not be delivered.