We have a lot of anti-spam capabilities in the platform and if you abuse the service to send actual spam, your account may be rate limited or blocked. But if what you are sending is good email and we don't see signals to indicate it is abusive, then there aren't any limits on how much you can send.
There’s a UI for it in Cloudflare once you have a domain. Seems to work pretty well - emails from my new domain go to directly into inboxes, no spam markers I’ve heard of.
