Identification of data structures

user
#ID_user PK	int
*name	varchar
*surname	varchar
*email_adress	varchar
*User_type FK	int

                                                                                 

EmailMessage
#ID_email PK	int
* content	varchar
*email_adress_sender FK	varchar
*email_adress_receiver FK	varchar

Drafts
#ID_draft PK	int
*ID_user FK	int
content_draft	varchar

File
#ID_file PK	int
*ID_emailID_Message FK	int
*content_file	varchar

User_type
#ID_user_type PK	int
*name	varchar