smtpd

secure, reliable, lean, and easy-to configure SMTP server

Install

All systems
curl cmd.cat/smtpd.sh
Debian Debian
apt-get install opensmtpd
Ubuntu
apt-get install opensmtpd
Alpine
apk add opensmtpd
Arch Arch Linux
pacman -S opensmtpd
image/svg+xml Kali Linux
apt-get install opensmtpd
Fedora
dnf install opensmtpd
Windows (WSL2)
sudo apt-get update sudo apt-get install opensmtpd
Raspbian
apt-get install opensmtpd
Dockerfile
dockerfile.run/smtpd
Docker
docker run cmd.cat/smtpd smtpd powered by Commando

opensmtpd

secure, reliable, lean, and easy-to configure SMTP server

The OpenSMTPD server seeks to be * as secure as possible, and uses privilege separation to mitigate possible security bugs * as reliable as possible: any accepted email must not be lost * lean: it covers typical usage cases instead of every obscure one * easy to configure, with a configuration syntax reminiscent of the OpenBSD Packet Filter's (PF) * fast and efficient: it can handle large queues with reasonable performance

postfix

High-performance mail transport agent

Postfix is Wietse Venema's mail transport agent that started life as an alternative to the widely-used Sendmail program. Postfix attempts to be fast, easy to administer, and secure, while at the same time being sendmail compatible enough to not upset existing users. Thus, the outside has a sendmail-ish flavor, but the inside is completely different.