Compatibility and Other Considerations
The following table (from Microsoft) shows supported client-server combinations for the on-send feature, including the minimum required cumulative update where applicable. Excluded combinations are not supported.
| Client | Exchange Online | Exchange 2016 On-Premises (Cumulative Update 6 or Later) | Exchange 2019 On-Premises (Cumulative Update 1 or Later) |
|---|---|---|---|
| Windows: Outlook Client Version 1910 (build 12130.20272) or Later | Yes | Yes | Yes |
| Mac:Build 16.47 or Later | Yes | Yes | Yes |
| Web Browser: Modern Outlook UI | Yes | N/A | N/A |
| Web Browser: Classic Outlook UI | N/A | Yes | Yes |
For more information, refer to Microsoft's documentation for On-Send Supported Clients and Platforms.
The Microsoft Outlook add-in is installed into the Outlook account and not the Outlook client. The following points should be noted:
- Only accounts that have the Outlook add-in enabled will have data protection.
- Additional accounts (personal or otherwise) that are added to the Outlook client will not have data protection unless those accounts have an add-in linked.
- Administrators can allow only corporate mailboxes to be added to Outlook accounts by following the instructions in the following Microsoft documentation: Allow only corporate mailboxes to be added.
- Since the add-in is account enabled, it will apply to all operating systems for that account. For instance, for a user that has both a macOS and a Windows machine, the add-in will be enabled for both of them. However, the endpoint agent has add-in support for macOS and uses injection-based plug-in support on Windows i.e. the Windows agent does not use the add-in.
- There are some Microsoft limits associated with using Outlook add-ins that make use of the On-send function. For more details, see Outlook On-send Add-ins Limitations.