secrec and Eirikr70
I seriously considered deploying my own email server.
But most experienced home-labers I trust - strongly recommend against hosting email at home lab or any cloud provider because of heavy deliverability issues they call it a huge headache. They reluctantly admit that nowadays you can provide reliable mail deliverability only through a handful of big and established email providers.
Besides, I access my Nextcloud server through Tailscale without exposing it to the Internet directly. But on the other hand, I seriously doubt that I can provide enough security for my own email server which must be directly exposed to the Internet.