My life improved when clients, customers, and family began using iPhones and iPads. iOS simplified the challenge of configuring and using email on smartphones and tablet computers. The integrated Mail app on iOS performs reliably, connects seamlessly to Exchange servers, and is easy to configure. It has an extremely intuitive user interface, which makes reading and replying to messages on-the-go a breeze. Plus, unlike old BlackBerry handsets, there’s no dependency upon an intermediary messaging server between the smartphone and the email server. Life is just easier.

Then Microsoft introduced Outlook for iOS. In a push to encourage Office 365 hosted email and Office productivity suite adoption, the app was offered for free. Many iOS users and Apple offices have begun loading the program. However, users should be educated about the corresponding security risks, of which I suspect many are unaware.

First, industry professionals have reported Microsoft receives access to the end users’ email credentials. Obviously, that’s bad on several levels.

Second, based on the app’s architecture, Microsoft’s servers could act as a man-in-the-middle and intercept corresponding email communications. Again, that’s bad on many levels.

Now, if your organization is using Office 365 to power its email services, Microsoft theoretically already possesses access to this information, anyway. But if your organization manages its own email servers, and if one of the reasons your organization chose to deploy and administer its own email servers is because it values the security of its email platform, these elements should be concerning.

Even worse, Outlook for iOS doesn’t enforce ActiveSync policies. Organizations have become accustomed to requiring end users to enter a passcode to access their smartphones and tablets when sending/receiving corporate mail on mobile devices. With the Outlook app, however, users can bypass that requirement. As a result, many firms will conclude that Outlook use on an iOS device is unacceptable.

The security concerns don’t end there, though. Since Microsoft includes integrated connections with OneDrive and other cloud-based storage providers, it becomes potentially easier for a corporate employee using Outlook on an iOS device to move sensitive, proprietary or closely held company information outside the company using one of those services.

On the other hand, iOS Mail works reliably, and organizations are familiar with its security mechanisms. Until Microsoft has a chance to tweak the Outlook app’s security, Apple users will be better served using iOS’ integrated Mail app.

Which email client app do you prefer on your iOS devices? Share your reasoning in the discussion thread below.