Minecraft Server with Pterodactyl; need email service

I'm like 80% of the way to having an mc server with pterodactyl, I just need to figure some stuff out on my own, but what I don't know is how to set up the email service. I know according to the docs theres a command for it, but I don't know which SMTP service to use. Is there a free one I can use, or should I just host my own? My architecture is kind of weird, i have a private vm set up for pterodactyl, and im attempting to use a reverse proxy to get a vps to host the domain itself and make it publicly facing (because the server is hosted on a tailscale network, so we need to get it out of there somehow). The vps is just basically forwarding traffic to my server, and I dont really have a reason to host my own email server except for this... what do you guys recommend? The VM is on proxmox, so if we could either just host the mail server on that debian vm with the mc server or create a container for it that would be ideal.