Are images blocked on hotmail, yahoo, etc. too now? I've only used gmail for the past 5+ years. Either way though, it wouldn't really produce a random sample,

Are images blocked on hotmail, yahoo, etc. too now? I've only used gmail for the past 5+ years. Either way though, it wouldn't really produce a random sample, though maybe it would allow somewhat meaningful comparisons between separate email campaigns even if the absolute numbers aren't too meaningful.