How to apply signatures for aliases and shared mailboxes using Microsoft 365 Add-in?

The signatures created either with Import from Microsoft Entra ID (formerly Azure AD), manually, or by using the CSV file upload - can be deployed to the users with aliases or shared mailboxes with the Add-in installed on the following Outlook version:

Platform	Outlook version	Supported version and later
Windows	- Microsoft 365 subscription - retail perpetual Outlook 2016 and later Note: Retail versions only! (for now, volume-licensed versions don't include the necessary API requirements sets)	from Version 2104, build 13929.20296 or above
Mac	- new UI Note: Only the New Outlook interface is supported (go to Outlook > New Outlook to enable it)	from Outlook Version 16.38.506
Web browser	- Modern Outlook UI when connected to Exchange Online: subscription, Outlook.com	-

Note: If you have an Office 2021 LTSC or any other oldest Office with an old Outlook version, please update them to the newest version specified above.

Also, you can check the Microsoft article Outlook JavaScript API requirement sets for more details.

Next, please follow these steps to apply signatures for aliases or shared mailboxes using Microsoft 365 Add-in:

Step 1. Set up an integration with Microsoft Entra ID (formerly Azure Active Directory).
Please follow our guide on how to register the Microsoft Graph App On Microsoft Azure.

Step 2. Deploy Office Add-in centrally to the users in your organization by installing it through the Microsoft AppSource.

Step 3. Create signatures for your aliases using AD import, CSV upload, or manually fill in the information.

Note: If you want different signature designs for each of your aliases, use the Duplicate master feature to create a new department and edit a Master signature design.

Step 4. After the add-in is installed and the signatures for each of your aliases are ready, click Deploy > Deploy to Outlook.

Step 5. The pop-up next shows the list of the signatures you created. The signatures created based on Microsoft 365 accounts will be automatically associated with the email addresses of these accounts. For manually created signatures, please associate the signatures with particular email addresses/aliases to deploy signatures to.

Step 6. After inserting all the necessary aliases' email addresses, click Verify users for the Newoldstamp app to check whether the email addresses exist within the Microsoft Entra ID (formerly Azure Active Directory).

Step 7. After verifying all email accounts, click Deploy to start the signatures roll-out.

Note: When the deployment has been completed, all the signatures you deployed should have an "Installed" label.

Step 8. When you compose a new email, choose alias email in the From: line, and the signature deployed for the alias will appear.

Should you need any help, please do not hesitate to reach us at support@newoldstamp.com.