Actually the client doesn't but we also have another version which runs in the cloud. Old versions of the ipad app were hooked up to that, newer versions are completely stand alone so that has also changed in the mean while... hey what can I say, we move fast :-)
What was the benefit of such an arrangement? My email server is already "in the cloud" so to speak. As it's a downloaded app, what value was added from a man in the middle, as it were?
Well the cloud is always on and online. Additionally we want to work with metadata which we want to store in the cloud and is not supported by for ex. the IMAP protocol. I can't go into to much details regarding our product roadmap but having a cloud backend really helps.
Another concrete case is new email notifications. When our ipad is not the active app we simply are not able to inform you when new mail arrives (due to apple background app restrictions). With a client/cloud hybrid we can do the heavy lifting on the client and use the cloud for example to send notifications when new mail arrives.
The cloud is always on and online? I don't mean to be argumentative, but your cloud apparently couldn't handle the load. Downloading an email client shouldn't require a "hit by a bus" analysis of the app's creators.
An app can store metadata locally; no need to have that on your servers. No doubt you can do some interesting things by having a server-side infrastructure, but I'm concerned about the security implications. If your server gets hacked, an attacker would have access to all of my email. Not to mention that you would have access to all of my email and why should I trust you?
