If your company firewall settings require domains to be added to a whitelist then you will need to add the following domains to the list:

• *.screenstepslive.com: The * represents your ScreenSteps account name.
• *.screensteps.com: ScreenSteps delivers media files from media.screensteps.com and other files using other subdomains of the screensteps.com domain. 
• www.bluemangolearning.com: ScreenSteps checks this domain for updates to the desktop software.
• media.screensteps.com: ScreenSteps delivers images hosted on Amazon S3 through this domain.

ScreenSteps uses port 443 for secure connections.