Mail Server Address help

[Ansry User 01]

for an email address it is in the format of user at domain.com
this supports many users, in theory, close to infinite

is it possible to have an email address in the form of domain.com

of course this would only work for one user, but in theory, if my name was kiran Smith, could i have an email set up as kiransmith.com and if so, how would i go about doing so?