CREATE TABLE parties (party_email VARCHAR(255), party_id VARCHAR(255)); CREATE TABLE party_services (customer_id VARCHAR(255))
Which is the email of the party that has used the services the most number of times?
    
SQL: SELECT t1.party_email FROM parties AS t1 JOIN party_services AS t2 ON t1.party_id = t2.customer_id GROUP BY t1.party_email ORDER BY COUNT(*) DESC LIMIT 1