When Roaming Captive Portal is used as WSS access method, Office 365 desktop application fails to get connected. The connections status will remain in “Trying to Connect” and clicking on the Send/Receive button will return a “The server is not available. Contact your administrator if this condition persists” error.
Web Security Service
Roaming Captive Portal Access method
Office 365 desktop application
This issue is due to a limitation in authenticating applications that are known to fail with cookie based authentication, such applications may not work with Roaming Captive portal access method.