The guiding rule.
Exchange server 2013+ and Outlook version 2013+ support Microsoft Office Add-ins.
Hence, if your company has Exchange 2010 and Outlook 2016. Your company will not be able to use Office add-ins from Outlook. Because minimum requirements are Exchange server 2013.
Microsoft resources available:
Outlook add-in deployment
For on-premises and online environments, you can deploy Outlook add-ins via the Exchange server.
Outlook add-in deployment requires:
- Office 365, Exchange Online, or Exchange Server 2013 or later
- Outlook 2013 or later
To assign add-ins to tenants, you use the Exchange admin center to upload a manifest directly, either from a file or a URL, or add an add-in from AppSource. To assign add-ins to individual users, you must use Exchange PowerShell. For details, see Install or remove Outlook add-ins for your organization.