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If whitelisting traffic filtering by domain is preferred. Please allow the following.
*.sharpencx.com - main app domain
*.sharpen.cx - supplemental main app domain
*.cx.shpn.co - dotCX domain
*.sipvbx.com - voice infrastructure domain
*.fathomvoice.com - legacy api domain
*.s3.amazonaws.com - long-term storage domain for audio and image files
*.yealink.com - Yealink registration domain
*.ckeditor.com - visual editor/UI library domain
*.loggly.com - logging tool domain
*.pendo.io - logging tool domain
*.ingest.io - logging tool domain
*.gstatic.com - font library domain
*.googleapis.com - font library domain
*.fontawesome.com - font library domain
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