In California, how many delivery receptacles are there in the community post office that has the highest number of delivery receptacles?
in California refers to name = 'California' and state = 'CA'; 'Community Post Office' is the Type
SELECT COUNT(*) FROM state AS T1 INNER JOIN zip_data AS T2 ON T1.abbreviation = T2.state WHERE T1.abbreviation = 'CA' AND T2.type LIKE '%Community Post Office%' AND T1.name = 'California' AND T2.state = 'CA'