Courtesy of Think Geek (who have some of the best use of symbols in subject lines I’ve seen).
- laura on FAQ about opens and Gmail caching
- NetGains Technologies Pvt Ltd on FAQ about opens and Gmail caching
- Google change breaks email open, location and device tracking on FAQ about opens and Gmail caching
- Derek Harding on More info about Gmail image caching
- Gmail Takes Away Data With Image Caching - What Does This Mean to Email Marketers? - My Blog | My Blog on Gmail deploys image proxy servers