Centralized deployment of the signature preview add-in

CodeTwo Email Signatures for Office 365 Add-in can be centrally deployed to all/selected users in an Office 365 organization. In this article, you will find step-by-step guidelines for Office 365 administrators.

There are two ways to perform centralized add-in deployment:


If you selected client-side mode when registering your tenant, do not install this add-in. Instead, deploy the CodeTwo Signatures Add-in for Outlook to your users as described in this article.

This add-in should only be used if you selected server-side mode or combo mode when registering your tenant. In the case of combo mode, the add-in will be used to preview emails sent through the CodeTwo Email Azure Service only. To have full functionality in combo mode, users need the CodeTwo Signatures Add-in for Outlook - see deployment guidelines.

Add-in deployment via Microsoft 365 admin center
(Office 365 admin center)

Centralized deployment via the Microsoft 365 admin center is the recommended approach because it supports deployment to groups of any size. The deployment via the Exchange admin center is not possible for groups with more than 1000 members.

To deploy the add-in to users/groups via the Microsoft 365 admin center, you need to be a global admin of your Office 365 organization. Learn more about admin roles in Office 365

First, you need to log in to Microsoft 365 admin center and go to Settings > Add-ins. Click the Deploy Add-In button (Fig. 1.).

ESIG 365 add-in central deployment admin center 1
Fig. 1. Deploying a new add-in in Microsoft 365 admin center.

A new window appears. Click Next and click Upload custom apps in the Deploy a new add-in section.

Select I have a URL for the manifest file and type the following address:


as shown in Fig. 2. Make sure to include the https:// protocol specifier in the URL. 

ESIG 365 add-in central deployment 2 url
Fig. 2. Providing the URL of the add-in.

Click Upload.

Now, you can assign users who will have access to the add-in and configure how the add-in will be deployed to these users (Fig. 3.). Select the deployment scenario that best matches your preferences and click Deploy. (Note that if you choose the Available option, each user will have to turn on the add-in manually.)

ESIG 365 add-in central deployment admin center 2
Fig. 3. Configuring the add-in's accessibility and deployment method.

You need to wait up to three minutes for the manifest configuration to finish. You will be notified when the add-in deployment is complete (Fig. 4.).


The add-in might not be visible for all of the users right away. The deployment usually takes a few minutes, but might take longer (up to 12 hours, according to Microsoft) depending on the number of users. Some users might need to restart their Outlook to see the new add-in.

ESIG 365 add-in central deployment admin center 3
Fig. 4. A successful deployment of the new add-in.

You can close the add-in deployment window now or click Next to learn how to announce the add-in to your users. Either way, the add-in is now visible in your Microsoft 365 admin center (Fig. 5.).

ESIG 365 add-in central deployment admin center 4
Fig. 5. The signature preview add-in appears on the list of add-ins.

Once the add-in is deployed to Office 365 users, they will be able to display the add-in pane with a signature preview while composing emails in Microsoft Outlook, Outlook for Mac, or Outlook on the web (Fig. 6.). See this article to learn more.

ESIG for O365 signature preview OWA 2
Fig. 6. The signature preview pane in Outlook on the web (OWA).

Add-in deployment via Exchange admin center (EAC)

See this Knowledge Base article for step-by-step instructions for Exchange administrators.

See next

Previewing email signatures in Outlook

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