Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues

Proxmox Mail Gateway - Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.

Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.

SpamAssassin - Use this program to "Unspam" your mailbox(es).

Newton Mail - Newton is a fully featured mail client available for Android, iOS, macOS and Windows.

Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...