Not Sure About this Term Buddy "google treat my mail as spam?"
But Possible of Chances is High. Think as you're sending Email to 1000 people, In that case 500 won't be active no more. In Remaining 500 out of 200 will Check Email Regularly. If 100 of them report your mail as Spam. Then Google will definitely take spam action. Better option send 100 or 50 Emails per day