My IT Director recently noted some suspicious activity on our proxy from letsencrypt.org and noted it was coming from my PC (along with a few others). I work directly across from him, so he found me first. I'd never heard of this site, so I agreed it sounded fishy.
Ironically, I was in the process of Sharing data from ArcGIS Desktop (Advanced) to ArcGIS Online. I recently began having problems sharing to ArcGIS Online, so I've been forced to use my laptop to publish, which actually bypasses our WiFi proxies. From the laptop I have no issues publishing data.
My question is: does ESRI employ this Let's Encrypt site during the upload process? Is there a certificate I would need and/or our proxy is blocking it and that's why I can't publish from my Desktop GIS?