Why do you not include the www in email addresses?

Question

What happens if you do? If you use the www. will it work?

Answer 1

the word addresses you use like www.yahoo.com are like entries in a phone book. To call Joe Smith you look up the name and dial the number. To call up www.yahoo.com, your web browser or email "dials" 69.147.114.210 The reason you use names is because they are much easier and friendlier. emails don't use www because www stands for world-wide web and it might confuse people. I don't think it will work if you do use www in them because that isn't listed in the "phonebook" for the email

if you notice, many times you don't need to put www in an address anyway

for illustration, go to www.dnsstuff.com at the bottom of the page and where it says
"DNS Lookup"
"Look up a DNS record (A, MX, NS, SOA, etc.)"
type yahoo.com and
pick "A" for a website
and "MX" for email (Mail eXchange)