I agree with pwg that postfix is fairly straight forward but to answer your question there are debugging programs that capture email such as mailpit [1] but I d

I agree with pwg that postfix is fairly straight forward but to answer your question there are debugging programs that capture email such as mailpit [1] but I don't know if you would consider that to be easier. I have not tried it out yet as I have always used smtp-sink for debugging part of postfix tools. Mailpit has a nifty web UI and claims to process 70 to 100 emails per second. The reason I suggested Postfix is due to the nature of it being on many internet facing servers and being battle-hardened over the decades and having started off very secure. Anything else should probably be confined behind bubblewrap and AppArmor or SELinux. Regardless of what tool you end up using consider adding firewall rules to explicitly block outbound SMTP in the event someone finds a way to relay through whatever tool you end up using as a bumper-guard against configuration mistakes and bugs. [1] - https://github.com/axllent/mailpit https://github.com/axllent/mailpit