How exactly does webmail forwarding work?

Question

Google

The main problem of the company - Google reports exceeding traffic limits
. When I asked the subcontractor - whether it is necessary to rearrange A-records on his server - he said - we don't work like that, just do forwarding and write SPF / DKIM.
What's the catch - it turns out anyway the data will go through Google and the problem of traffic will remain? Or am I misunderstanding the forwarding mechanism?

Answer 1

Yes, they will go through Google and you will not gain anything with such forwarding.