I found some information on how to manually in Boxer set what domains are internal so boxer can highlight and show an asterisk of email addresses that are external. It mentions it can be set globally though. Anyone know how to do that with Boxer for all our clients?
Have you tried this appconfig?
Configuration Key Value Type Configuration Value Description
|AppDomainsInternal||String||Provide the list of internal domains. For example, [vmware.com, air-watch.com].||Define the domains that are internal or permitted. The user can disable the warning using the 'Confirm before sending' setting in Workspace ONE Boxer when the internal domains are defined and AppDomainsWarning key is not set.|
False - disabled (default)
True - enabled
Set to True to enable warning when the user enters recipients from external domains. If the domains are configured and the AppDomainsWarning value is set to True, the 'Confirm before sending' setting is unavailable to the users. When the warning is displayed, the user can either Accept and return to the Compose email menu or Ignore and continue sending the email to external recipients.
The OP doesn't mention if he's referring to highlighting external senders when drafting an email or when receiving an email. The appconfig shown allows you to see external domains when drafting an email. I could have sworn Boxer used to have the ability to display when an email was received from an external recipient, but I can't figure out how to set that.