SpamAssassin - Use this program to "Unspam" your mailbox(es).
TinyWall - Lightweight and non-intrusive firewall
MailScanner - MailScanner is a open source email security system design for Linux-based email gateways.
Windows 10 Firewall Control - Windows 10 Firewall Control: simple and exhaustive solution for applications network activity controlling and monitoring.
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...