This list doesn’t include all @Microsoft properties, just second-level domains that load on HTTPS, plus microsoftonline.com and windows.net, which load on HTTPS with some subdomains only.
I collected them by combining Outlook.com assets[^4] and second-level domains from Office-configuration files[^1][^2]
These are in alphabetical order except the first entry, whence @1Password supplies its rich icon.[^3]