Postfix - Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.
Trend Micro Deep Security - Excellent hybrid cloud security doesn't require your business to sacrifice operational performance. Trend Micro lets you keep business moving securely.
mailcow - An open source mailserver suite.
AWS IoT Device Defender - Manage the security of your fleet. With AWS IoT Device Defender, you can audit and monitor device configurations. Get started today.
Mail-in-a-box - Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software and also includes contacts and calendar synchronization.
Azure Sphere - Help protect your connected IoT devices, such as MCUs and crossover modules, development kits, and guardian devices, with Azure Sphere.