Allow remote wipe of data from device
We are considering Boxer in my organization as an alternative to TouchDown. A nice security feature TD has is the ability to wipe all application data by sending an email to yourself with a predetermined passcode and subject.
This is useful for devices that aren't managed using MDM - in case the device was stolen, I'll email myself with the predetermined subject, and all stored emails on the device should be wiped.
As an aside, it'll be great to see some white papers on your security protocols, standards and encryptions. If you are to be a serious contender in the corporate landscape, people would want to see those - we weigh these things carefully before picking an app.