I would like to make class diagram for (Create Account, Email Confirmation, and Account Activation):
#User registers for an account on System
#User enters the following data:
- username
-user email

# Chosen User Identifier for the account - System must ensure the user id is at least 5 characters, and no existing accounts with the same user id
- If same user id exists, System must require User to choose another user id

#Password - System must ensure the password must be at least 9 characters but no more than 18 characters long. Password must contain some upper case and lower characters, some digits, and some special characters such as $, !, #, -, etc...
-- For example, CSUF-spring2015
# User submits account registration form è Must use GRASP and/or GoF patterns to create and store new account information
# Upon account registration submission, System sends an email to User è Must use GRASP and/or GoF patterns
# User must activate the account upon receipt of email within 15 days (adaptable)
-System will remove account if User does not activate the account within 15 days

The classes that you should use it:

• Model
• View
• Controller
• DBHandler
• EmailHandler