Just curious, based on your research, are people really concern about security of their confidential emails?
When do the access to better features outweight the need of security?
If you use Mailbox, they actually temporarily hold on to your rebounce emails as well. Other email apps such as Skimbox, the emails are stored in their MongoDB server. Obviously the value of this 2 applications, granted they are still alive and used by folks, then the features > security concern. Not that they are compromising your messages anyway.
I am sure different people have different priorities. Just a curious question based on your findings.
Btw I also called myself an aspiring entrepreneur in most of my email introductions. I think its just my humble way of saying I am working on it and dedicated to growing - as oppose to being too boastful when asking for advice.
Find me @ http://www.linkedin.com/in/garyyauchan/
Also love to get your feedback for Hashtags for Email @ https://news.ycombinator.com/item?id=6948659