What’s Up with the @ Sign?

All e-mail addresses are made up of two parts: a recipient part and a domain
name. An @ symbol separates the two parts to denote that a recipient is
unique within a domain name. The domain name is usually the name of your
ISP (or your company if you have e-mail there), and, like a website, an e-mail
domain has an associated IP address. This allows (actually, requires) the use of
a DNS server to translate the domain name portion of an e-mail address to the
IP address of the server where the e-mail account resides.
The recipient part is the chosen identifier that you are known by within the email
domain. There are a lot of possibilities for choosing the recipient. Here
are a few popular styles:
Firstname.Lastname John.Brown
FirstinitialLastname JBrown
Nickname DowntownJohnnyBrown
Personalized license plate L8RG8R
Other obscure reference GrassyKnoll63
When picking an e-mail address, remember that sometimes you’ll have to verbally
tell someone your e-mail address, so “X3UT67B” is inadvisable.