MxToolBox - All of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool.
Egnyte - Enterprise File Sharing
intoDNS - IntoDNS checks the health and configuration and provides DNS report and mail servers report.
ManageEngine ADAudit - ManageEngine ADAudit is a real-time windows active directory auditing tool.
DNSInspect - DNS is a free online service to check your domain’s servers for common DNS and mail errors and produces a report with explanations how to fix them.
StealthAUDIT Management Platform - STEALTHbits Technologies is a leader in the Microsoft Infrastructure and Application Management space, with solutions for Data Access Governance, Identity Access Management, Active Directory, and more.