External recipients MailTip offline behavior update for Microsoft Outlook for iOS and Android

Updated November 15, 2024: After further review we have decided not to proceed with this change at this time. We apologize for any inconvenience. 

This feature update expands how Microsoft Outlook for iOS and Android gives external recipient warnings.

When this will happen:

 We will communicate via Message center when we are ready to proceed.

How this will affect your organization:

A new optional administrative setting (InternalDomains) allows your organization to configure a list of internal domains to inform the external recipients warning in Outlook for iOS and Android. If set, this list of domains will be used to make determinations for external recipient warnings rather than the MailTip service

This feature update is available by default.

What you need to do to prepare:

Manage the option to provide a list of external domains to provide external recipient MailTip warnings by Outlook for iOS and Android. For more information, see External recipients MailTip domain configuration.

You may want to notify your users about this change and update any relevant documentation as appropriate.