Office.cast.item property

Provides IntelliSense specific to compose or read mode messages and appointments.

Hosts: Outlook
Available in Requirement set Mailbox
Last changed in 1.0
Applicable Outlook modes Design time in Visual Studio only

Return value

A set of methods that enable you to select the appropriate IntelliSense for your Outlook add-in.


This property and its methods support IntelliSense for developing Outlook add-ins on Visual Studio only. They do not have any effect on other development tools.

The Office.cast.item methods are used at design time in Visual Studio to provide specific IntelliSense for the Office.context.mailbox.item property. When you use the toAppointmentCompose method, for example, IntelliSense will show only the Appointment methods and properties that apply in compose mode.

At run time, the Office.cast.item methods have no effect on your Outlook add-in.


The following example uses the toMessageCompose method to cast the Office.context.mailbox.item property so that it will only show IntelliSense for the Message object in compose mode. After the cast, the message variable will only display IntelliSense for methods and properties that can be used in compose mode.

var message = Office.cast.item.toMessageCompose(Office.context.mailbox.item);

Support details

A capital Y in the following matrix indicates that this method is supported in the corresponding Office host application. An empty cell indicates that the Office host application doesn't support this method.

For more information about Office host application and server requirements, see Requirements for running Office Add-ins.

Office for Windows desktop Office Online (in browser) Outlook for Mac
Outlook Y Y Y
Available in requirement sets Mailbox
Minimum permission level Restricted
Add-in types Outlook
Library Office.js
Namespace Office

Support history

Version Changes
1.0 Introduced