Support multiple accounts with different providers, but through a simple unified interface. Do what apple does in their mail app and default the settings where you can .. e.g. put in the default mailserver details for known providers.
Support for delay 5 mins then send to stop accidental sends.
Easy attach pictures or files - 1 or two taps.
If you need to do something CPU intensive (e.g. resize the 10MB image to 500k - do it in a thread in the background - dont make me wait, free up the UI!)
Let me view attachments inside your app (images, pdf, xls, doc minimum)
Support alerts for important emails (e.g. simple regex or string matching rules, if you get email that matches rule, then alert like crazy - ring the phone if you can - until I've acknowledged it)
Support for delay 5 mins then send to stop accidental sends.
Easy attach pictures or files - 1 or two taps.
If you need to do something CPU intensive (e.g. resize the 10MB image to 500k - do it in a thread in the background - dont make me wait, free up the UI!)
Let me view attachments inside your app (images, pdf, xls, doc minimum)
Support alerts for important emails (e.g. simple regex or string matching rules, if you get email that matches rule, then alert like crazy - ring the phone if you can - until I've acknowledged it)