GMail supposedly downloads, caches and proxies all images to prevent tracking: https://arstechnica.com/information-technology/2013/12/gmail-blows-up-e-mail-mar

GMail supposedly downloads, caches and proxies all images to prevent tracking: https://arstechnica.com/information-technology/2013/12/gmail-blows-up-e-mail-marketing-by-caching-all-images-on-google-servers/ https://arstechnica.com/information-technology/2013/12/gmail...