If the ExtendSync for Outlook icon is missing or appears grayed out, it’s typically due to how Outlook manages add-ins based on message type, reading pane visibility, or mailbox configuration.
This article explains the most common reasons why add-ins are unavailable and how to restore the ExtendSync icon.
When Outlook Add-Ins Are Unavailable
Outlook add-ins are available only for messages or appointments while composing or reading not for other item types.
Microsoft disables add-ins (graying them out in the ribbon bar) when the current item meets one of these conditions:
Scenario | Effect |
Reading Pane is hidden (View → Reading Pane → Hidden) | Add-in grayed out |
Message is encrypted, digitally signed, or protected by Information Rights Management (IRM) | Add-in disabled |
Item is a delivery report or system notification (IPM.Report.* class) | Add-in disabled |
Email is a draft (in Drafts folder, no sender assigned) | Add-in unavailable |
A .msg or .eml file is attached to another message or opened from your file system | Add-in unavailable |
Item is in a shared, archive, or public folder mailbox | Add-in disabled |
Item uses a custom Outlook form | Add-in unavailable |
💡 Note:
If you’re using a shared mailbox, check this Microsoft article to confirm whether your version of Outlook supports add-ins for shared mailboxes.
Desktop Outlook Users
If you're using desktop Outlook, Microsoft only displays the add-in while you are viewing an email.
With Reading Pane Off
If your Reading Pane is turned off (View → Reading Pane → Off):
Add-ins, including ExtendSync, will not appear in the Home tab.
You’ll only see the ExtendSync icon under the Message tab when an individual email is open.
With Reading Pane On
Most users have the Reading Pane enabled (View → Reading Pane → Right or Bottom).
With it turned on:
The ExtendSync add-in will always appear under the Home tab in the Outlook ribbon bar.
You can access ExtendSync directly while previewing emails.
Outlook Add-In is grayed out
If the ExtendSync icon is visible but grayed out, Outlook is preventing add-in activation because the current message is not in an active reading or open state.
To fix this:
Click View.
Select Reading Pane.
Choose either Right or Bottom.
Once the reading pane is turned on, the ExtendSync icon should become active.
For Outlook Web Access (OWA) Users
In Outlook on the Web, the ExtendSync icon appears at the top-right corner of your email, near the reply/forward icons.
If you don’t see it there, it may be hidden in the three-dot (⋯) menu.
Make the CloudExtend Icon Always Visible
At the top of the Outlook page, click Settings → View all Outlook settings.
Navigate to Mail → Customize actions.
Under Message surface, select the checkbox for ExtendSync.
(Optional) Adjust the order in which icons appear by dragging them into your preferred sequence.
Click Save.
You should now see the ExtendSync icon consistently at the top-right of your email view.
