Notes on setting up a mail server

As part of my public homelab setup, one of the services I configured was a mail server! I got started with around a month ago, and have been running a bare minimum setup for a week. Here are some notes about the configuration process. Finding the right infrastructure Most providers and ISPs block port 25 traffic due to it being an easy target for spam. It makes sense to do so, as even one machine sending spam would put the entire network on a blocklist, unable to send email. Some providers have an option to request to unblock the port. Vultr is one such provider I heard of, so I started by hosting my website there, and submitted an unblock request within a few days that was eventually rejected. That left me with two options: Switch to a provider that allows SMTP traffic Use an external service called a SMTP relay to handle sending and self-host receiving email. The second option is the approach I saw recommended most often, as it delegates the responsbility of maintaining sender…