Actually no, you just give them your cloudflare API token and all the configuration is done for you.

It's not like setting up a custom domain on, say, protonmail where you have to set DMARC records etc

You just "add domain" then click "new mailbox".

Anyways - I would like to change tack and offer you guys some encouragement, I like what you are doing (encouraging the move away from centralised big tech), and $39 isn't actually that bad when you consider the cost and hassle of hosting, I just think you should be a bit more honest and straightforward in your marketing that's all.

Claims like "free for stackers" (actually, just one year), "FOSS-as-a-service" (but the service isn't FOSS) and "100% private" (when this part cannot be verified, and ultimately still runs on servers you control) are misleading at best.

The service honestly sounds good just don't sell it as (or make it sound like) something it isn't, that's literally my only beef anyway.