I withdraw one star because Spark needs one email account to sync my account data and that leads me to the privacy concern. Even Outlook doesn’t save my email account for email sync. I would love to use it again until Spark provides the option SKIP saving my personal emails. Thank you~—-Definitely the best email app I have ever used. Simple, fast and highly configurable. There are only few tiny issues such as display of email written in outlook and the AD integration in enterprise network, but nothing more. Spark is a great app and I appreciate all the effort contributed by Spark team. Bravo!