hetzner and sending emails

I work with a lot different clients and using 3rd party relays price is creeping up.

With hetzner I been able to already build and use a smtp custom relay that actually works great. There is zero issues so far.

However I am hesitant to move traffic and start sending large volumes of email though it.

My concern is they would ban me for spam if a ton e-mails were sent from my customers though anything hosted by them.

I may just continue to use 3rd party relay or seek an alternative service if the risk is too high with hetzner TOS and want to hear what people have experienced with them.