The best email apps for iOS 9

Email's the one true killer, universally used, app. But which smartphone email app for iOS 9 best meets your specific business needs? Here's a quick rundown of popular options.

Image: James Martin/CNET

In February 2015, I recommended Apple users stick with iOS' integrated Mail application. At the time I noted several security concerns that might concern enterprises whose iOS users were loading the iOS Outlook app.

That was before Apple released iOS 9, Microsoft updated its Office suite, and a variety of other iOS email apps were fine tuned. Now iOS users are deploying iOS 9, and it's time to revisit the question: Is iOS 9's integrated Mail app the best option?

Unfortunately, there isn't a simple yes or no answer. Ultimately, the correct choice requires a special blend of elements of which only you know the particular mix. The best iOS 9 email app for you will be one that meets your unique blend of needs, which may or may not include security concerns, Exchange compatibility, calendar integration, contact management, or customizable Notifications. After experimenting with several iOS 9 email apps, I have some observations that can assist you in better selecting the app that might work best for you.

Apple iOS 9 Mail

Still the standard-bearer, Mail provides a graceful, reliable email interface that's easy to configure. The app supports Exchange, POP3, and IMAP, as well as iCloud, accounts. It integrates well with the native iPhone Calendar and Contacts apps.

Important to me, when turning an iPhone to landscape mode, Mail switches to landscape mode, better enabling the use of both hands in composing email messages and replies. The app is also well-integrated with the Apple Watch.

If you're like me, you read, review, move, and respond to hundreds of messages each day. Mail makes it easy to process a multitude of messages. While viewing an email, if you delete it, you are taken immediately to the body of the next message. It's seemingly an insignificant behavior, but the feature saves significant time over the course of an entire day when processing hundreds of messages.

Microsoft Outlook for iPhone

Microsoft addressed security concerns with its Outlook for iPhone app midyear. The fairly lightweight app (the program is a 54 MB download) enables reclassifying emails to provide higher priority messages with greater visibility. The program also extends archiving and scheduling, as well as deleting and moving, capabilities to the iPhone. Microsoft OneDrive, Dropbox, and even Google Drive support open Outlook to integration with cloud-based storage providers, including the non-Microsoft variety. Like Microsoft's OWA for iPhone app, the program also communicates with the Apple Watch, if that's important to you, providing Notification updates on your wrist.

Particularly impactful is the app's support for landscape-mode composition. Drafting messages and writing replies is much easier when you can use both hands to type.

Microsoft Outlook for iPhone also packs an attractive calendar view that essentially mimics that which desktop users are accustomed. Users afraid of change or those preferring standardized views across all devices will likely find Microsoft's iPhone Outlook app a justifiable download for that reason alone.

When processing a multitude of messages, Microsoft Outlook for iPhone returns you to the Inbox view after deleting a message. If you process messages individually, that method slows you down. However, Outlook boasts an intuitive method by which you can momentarily press a message and convert the Inbox display to supporting marking multiple messages for deletion, simultaneously.

Microsoft OWA for iPhone

Microsoft also offers an OWA app for iPhone. A quick 8.3 MB download, OWA provides a web-appearing email interface that resembles Microsoft's Outlook Web Access portal. While a self-contained app that doesn't leverage the iPhone's browser, OWA offers access to the Exchange user's Mail, Calendar, and Contacts. The application doesn't support composing messages in landscape mode, but it does enable configuring automatic out-of-office replies, so I keep it on my iPhone for that one reason.

Google Gmail

Google offers iOS email apps, too. Gmail is among the most popular. The 17.7 MB download enables attaching photos and documents from other iOS apps, permits quick archiving and replying directly from an email notification, possesses features designed to help automatically sort social and promotional mail and includes integrated search functionality.

Deleting a message, as in Outlook, returns you to the Inbox view; however, you can process multiple messages quickly by selecting checkboxes on messages appearing within the Inbox and selecting the Trash or Archive icon. There's also a drop-down menu that enables specifying multiple messages as spam or moving multiple messages to the same folder simultaneously.

With support for landscape mode composition, drafting detailed messages quickly is much easier compared to having to compose a message using portrait mode only. Overall, Gmail offers a convenient email app that feels clever and intuitive when using on the fly.

Inbox by Gmail

Google's Inbox by Gmail strives to remove the stress associated with managing an Inbox. The app displays instant highlights, eliminating the need to "dig through emails," as Google describes the old traditional method of locating information. Reminders are easily added at the top of the Inbox. Email messages and reminders can be "snoozed" to enable addressing them later.

Bundles, meanwhile, enable grouping messages and clearing clutter. By default, Inbox offers the ability to bundle items by subject, including purchases, finance, social, promos, updates, forums, and low-priority messages.

Google states Inbox by Gmail works best when users leverage it on all their devices, including their computers, smartphones, and tablets. Using Inbox by Google doesn't preclude using Gmail and doesn't replace Gmail; instead, Inbox is merely a new option for integrating reminders and email management. As with all the apps mentioned here, you'll have to give it a go to determine just how well it might accommodate your daily routines.

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