Domain server tools

• MX Toolbox
• DNS Propagation Checker (Check DNS resolving across the world + CDN’s)
• Online DNS Record Viewer
• NetCraft Site report (Type of HTTP Server + DNS records)
• Check STARTTLS mail server support
• SSL Certificate Search histoy
• Symantec CRT check

MS Windows Server

• Test Exchange connectivity
• Windows Update Catalog

Security tools

• Mozilla Observatory – Security scan of web application and web servers
• Have i been pwned? – Check if you have an account that has been compromised in a data breach
• ID Ransomware – Identify who crypted your files

Other offline tools

• PARSEC – Parse, Analyse, and Report on Solaris Explorer Configuration/Content
• Easy RoboCopy – Easy RoboCopy is a graphical user interface for RoboCopy. It shows all available arguments on one form with descriptive names and tooltip help.

Other web tools

• MS Build Numbers – Build numbers and version history for various products (Microsoft)