How many complaints from customers with a gmail.com email were received by the company in February 2017?
gmail.com email refers to email like '%gmail.com'; in February 2017 refers to "Date received" BETWEEN '2017-01-02' AND '2017-02-28';
SELECT COUNT(T1.email) FROM client AS T1 INNER JOIN callcenterlogs AS T2 ON T1.client_id = T2.`rand client` WHERE (T2.`Date received` LIKE '2017-02%' OR T2.`Date received` LIKE '2017-01%') AND T1.email LIKE '%@gmail.com'