email share with clients

Hello,

My present client asking to send work and detail communication through email services. He has sent the Escrow. But I do not want to send work files and communicate through my personal email, as there are plenty options open in the main platform. First time I told him , this is against T&C of PPH. But he shows me a chat/email (i don't know) that I can use email. But this is not clear how far I can exchange matters with client. What should I do ? Please , I need urgent answer.

Thank you