One of the first things I noticed after signing up for a free account with Skiff, is that they have the standard "Block Remote Content" option which pretty much all email providers and clients have, but that the option is disabled by default. But the main problem, although they attempt to block remote content from loading on the iOS client when you enable that setting, they fail to do so when that remote content is loaded via one of the following html tags: One of the things the CEO said to me in the thread regarding blocking remote content was "There is no foolproof way to load any remote content without possibly exposing email open information".