New to Python, GMail SMTP error

I am writing a simple sendmail function to myself and I keep getting this error:

NameError: name 'SMTPException' is not defined

What is wrong with my code? Any suggestions?

import smtplib

sender = "user@gmail.com"
receiver = ["user@gmail.com"]
message = "Hello!"

try:
    session = smptlib.SMTP('smtp.gmail.com',587)
    session.ehlo()
    session.starttls()
    session.ehlo()
    session.login(sender,'password')
    session.sendmail(sender,receiver,message)
    session.quit()
except SMTPException:
    print('Error')