Adapting Add-ins to Outlook Ribbon Improvements: Technical Guide

Introduction

Microsoft is rolling out significant ribbon interface improvements for Outlook add-ins on the web and the new Outlook for Windows. These changes aim to harmonize the user experience across different Outlook clients while facilitating the discovery of extensions.

Ribbon Enhancements

Improvements include displaying the group name defined in the manifest, adding dropdown menus for quick access to commands, and a consistent interface in the overflow menu.

Key improvements implemented

The Outlook ribbon modifications introduce several major optimizations:

Custom group name display: The ribbon now displays the group name specified in your manifest rather than the generic add-in name from the Microsoft Marketplace
Contextual dropdown menu: A new dropdown appears next to the main button to facilitate access to the extension's commands
Enhanced overflow interface: The overflow menu also benefits from a similar dropdown to maintain consistency

Impact on User Experience

These improvements reduce the clicks needed to access your add-in's features and create a more intuitive experience for end users.

Configuration by manifest type

Unified Manifest for Microsoft 365

For add-ins using the Unified Manifest, the group name is configured in the label property of the corresponding group object:

{}JSON

1{
2  "extensions": [
3    {
4      "ribbons": [
5        {
6          "tabs": [
7            {
8              "groups": [
9                {
10                  "id": "msgComposeCmdGroup",
11                  "label": "Contoso Add-in"
12                }
13              ]
14            }
15          ]
16        }
17      ]
18    }
19  ]
20}

Verification Required

Ensure that the label property value accurately reflects the function of your command group to optimize user understanding.

Add-in Only Manifest

For traditional manifests, configuration is done via the group's <Label> element, with the value defined in the <ShortStrings> section:

<>XML

1<ExtensionPoint xsi:type="MessageComposeCommandSurface">
2    <OfficeTab id="TabDefault">
3        <Group id="msgComposeCmdGroup">
4            <Label resid="GroupLabel"/>
5        </Group>
6    </OfficeTab>
7</ExtensionPoint>
8 
9<Resources>
10    <bt:ShortStrings>
11        <bt:String id="GroupLabel" DefaultValue="Contoso Add-in"/>
12    </bt:ShortStrings>
13</Resources>

Recommended actions for developers

Audit existing manifest

Examine your current manifest to identify command groups and their associated labels. Verify the consistency of displayed names.

Update labels

Modify label properties to accurately reflect the group's functionality rather than a generic add-in name.

Test on target environments

Validate the display on Outlook web and the new Windows version to ensure visual consistency.

Update user documentation

Update your add-in documentation to reflect the new user interface elements.

Impact on developer experience

These improvements provide developers with more granular control over the organization of their commands in the Outlook interface. The ability to set explicit group names significantly improves the discoverability of features.

Compatibility

The changes are backward compatible. Existing add-ins will continue to work, but the group name display may differ from the current display.

Resources and training

To deepen your understanding of these developments, Microsoft recommends consulting the recording of the Office Add-ins community call from February 2026, which details the technical specifications and implementation best practices.

Useful links

Glossary

Add-in: Software extension that extends Outlook's functionality by adding custom commands and integrated user interfaces.

Manifest: XML or JSON configuration file that defines the properties, permissions, and extension points of an Office add-in.

Unified Manifest: New JSON-based manifest format that simplifies configuration and improves compatibility across Microsoft 365 applications.

Extension Point: Specific integration point in the Outlook user interface where an add-in can add its commands.

Overflow Menu: Dropdown menu that appears when ribbon space is insufficient to display all available buttons.

Ribbon: Outlook's main navigation interface that organizes commands into tabs and functional groups.