Electronic Mail
Forrester Research -- 
In 1992 2% of US population used e-mail 
Jan 1997 up to 15% 
By 2002 will be 50% 
Most popular Internet activity
People have mailboxes -- data files into which Internet software can
write incoming electronic mail (e-mail) -- even if that person is not
"logged on"
E-mail usually delivered in seconds
 
Route of e-mail messages may vary -- depending on paths available
 
If critical nodes are unavailable, e-mail may be delayed
 
Full e-mail address consists of
 
user-id@IP-Host-Name
fkjohnson@zeus.personnel.lilly.com