Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Documents_Mailed (mailing_date VARCHAR, document_id VARCHAR)

### Question ###
What is the mail date of the document with id 7?

### Accurate SQL ###

SELECT mailing_date FROM Documents_Mailed WHERE document_id = 7