Gmail saving all my sent mail in Sent folder, how to prevent?

eM client has some way to cleanup Gmail sent folder? I tried to disable option to save Sent mail. It had no effect. And after i restarted app, i still see e-mails being added to the Sent folder of the app. But when i login Gmail, my newly sent mails are saved here and i want eM client to remove these, i do not see Gmail config. option to not save sent mails… When i remove sent mail message from app, it does not remove that message from Gmail mailbox/Sent (i mean webmail on gmail web site).

Mybe i can setup new gmail fitler:
Contains words: label:sent
Action: Delete