[Environment]
Samsung Devices with the default Email app.

[Issue]
The following error occurs gets when trying to set up email in the Knox Workspace: 'Try again with network provider's default APN'

[Root cause]
This issue occurs when the Email app cannot connect to the EAS activation server https://api.samsungapps.com/activesync/activate/activesync. 

[Resolution]
This is due to a settings issue with the Firewall, VPN or the Proxy server. Please check these settings and the issue should be resolved.