Migrate to mail apps for Outlook Web App customization
Published: July 16, 2012
Learn how to customize Outlook Web App in Exchange 2013.
Applies to: Exchange 2013 | Outlook 2013 | Outlook Web App | apps for Office | Office 365
Starting with Outlook Web App in Exchange Server 2013, you have a new way to customize Outlook Web App: mail apps. Mail apps provide a single interface and programming model that use web standards to create a custom experience for your users. Your mail app can be simple or complex, use data from an Exchange server or from any service on the web, and fully integrate with both Outlook Web App and Outlook 2013.
You can install mail apps on an internal server to limit access to authorized users, or you can put your mail app on the Office Store and Apps for sale to the general public. Anyone who is running Outlook Web App or Outlook 2013 can download, install, and use mail apps from the marketplace.
Mail apps use the following standard web technologies in a collapsible frame on the client screen to enable your users to interact with the app:
XML – The manifest file that describes your mail app is an XML document. The manifest provides a description of your mail app, tells Outlook Web App where it can be found, and tells Outlook Web App the conditions in which to render the mail app. For more information about the manifest file, see Schema reference for apps for Office manifests.
HTML 5 – The user interface for your mail app is written in HTML 5, the emerging standard for web pages. For information about how to use HTML 5 to create a UI for your mail app, see Apps for Office UX design guidelines.
At least two servers are involved in delivering your mail app to Outlook Web App. The first is the Exchange server, which provides the user's mailbox and the manifest files for mail apps that the user has installed. The second is a web server that you maintain that provides the scripts and HTML that make up your mail app.
You can connect your mail app for Outlook Web App to any web service to provide information to your clients.
Connecting to EWS
For more information about using EWS in a mail app, see Calling web services from a mail app for Outlook.
Connecting to web services on your mail app web server
If you are using the .NET Framework for your service, the EWS Managed API includes a validation library that you can use on the server to validate the user identity token sent from the Exchange server. If you are using another programming language, such as Ruby or PHP, you can validate the token using those languages as well.
For more information about using the user identity token, see Authenticating a mail app by using Exchange identity tokens.
Web services from the Internet
Your mail app can also provide information from any web service on the Internet by using a proxy that runs on your mail app web server. You can't get data directly from another web service, the web browser will return a cross-site scripting error; however, your proxy web server can access and provide the information. You can use the user identity token to identify authorized users or to provide a single sign-on solution.
You can design the UI of your mail app however you like. Your mail app integrates into the reading experience for your user; it will run in a pane that is as wide as the reading area and is between 32 and 350 pixels tall. Within that area you can create the user experience that will make your mail app stand out.
The following are some suggested design guidelines for your mail app:
Use Microsoft design style – The new interface for Outlook Web App and Outlook is inspired by the Microsoft design style initiative.
Dimensions – Use the smallest dimensions that you can for your mail app. The mail app should blend in with the message reading experience.
Borders and margins – The Outlook Web App UI will display a border around your mail app. If appropriate, fill the UI with your app by setting the margins to zero.
Scrolling – Your mail app is displayed in a scrolling window. Adding another scroll bar can be confusing for readers. Use paging for long displays of information.
Navigation – When you use paging for your mail app, remember to include navigation both forward and backward through the content. You can use complex structures, such as pivots and tabs, to present structured information to your reader.
Design for the device – Mail apps can be shown on the desktop, on a tablet, or on a smart phone. You can usually use the same UI for a tablet and a desktop system, but you should provide a separate UI designed specifically for the reduced screen size of a smart phone for the best experience.
For a more detailed discussion of design guidelines for mail apps, see Apps for Office and SharePoint UX guidelines.
Mail apps for Outlook Web App and Outlook use standard web technologies; you can use the same tools that you use to create web sites to create a mail app. Visual Studio 2012 with the Apps for Office Tools provides an IDE for creating, deploying, and testing mail apps; however, you can use a text editor to create a mail app as well. To create your first mail app, see one of these two articles: