Since both the Gmail Android app and Gmail itself is made by Google, the app supports all features Gmail offers (like labeling/starring) and gets new features implemented early - usually as soon as they are announced.
Gmail brings much of the functionality and power of Google's search engine to the app's search. You can use operators such as label:, is:, OR, has: among others, define date ranges, limit search to specific groups and so on. And, you can do it all amazingly fast. The search will also try to
Nearly every other mail app has this ability. If you have more than one Gmail/email account or get a lot of email, this is a significant omission. *You can sort other, non-Gmail accounts linked to the Gmail app, but not Gmail accounts.
Inbox tries automatically bundling similar messages together. For example, Inbox will create bundles for travel information, receipts, promotions as well as group messages temporally. It enables also managing these bundles of messages together - they can all be swiped away together.
If an email contains pictures, flight information, reservation at a restaurant, attachments, links, dates, phone numbers and other information that the application recognizes, it will surface that information in its main view. These items can be viewed and interacted with without having to open the
CloudMagic has 'cards', that allow quick interactions with other services, like Evernote, MailChimp, Salesforce, Trello, etc. And unlike similar integration, these interactions happen within the app itself.
Microsoft Outlook comes with built-in cloud storage browser allowing you to attach files directly from services such as Dropbox, Box, Google Drive or OneDrive to emails and directly open attached files without the need for the main cloud storage app.
The app stores user information and credentials on outside servers which is a violation of ActiveSync password requirement policies. These security concerns have been enough of an issue that European Parliament has banned its members from using the app out of fear that it might lead to leaking sen...
Swiping an e-mail message from the inbox to the left gives an option to 'snooze' it for a set period of time. You can manually enter the date for when to return it to the inbox or choose from options like 'later today', 'this weekend', and 'someday'.
There's concern of privacy, because Mailbox has access to your emails, since they're passing through their servers. After being acquired by Dropbox these concerns have been somewhat alleviated, because of Dropbox's stable track record, but not completely.
Tasker is an automation app. Aqua Mail's Tasker integration allows changing settings, triggering message based events and running mail checks based on criteria like time of day, location, timer, connection type, etc.