Zabbix - Track, record, alert and visualize performance and availability of IT resources
SpamTitan - Comprehensive Email Protection. 99.99% Spam Detection. Blocks phishing, viruses, malware and other email threats.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Sanebox - SaneBox is a cloud-based service that allows users to filter and manage their emails.
Prometheus - An open-source systems monitoring and alerting toolkit.
ZeroSpam - Cloud email security & anti-spam solution