I've been trying to get our Exchange Server 2003 (SP2 on SBS) to force all messages sent to one specific external domain to go out as plain text even if the Outlook client sends as html. I've read and re-read and re-re-read KB821750, but no changes I make within the Exchange Organization\Global Settings\Internet Message Formats seem to have any effect at all. All messages go out as html format (which is what the Outlook clients are configured to do). In fact, for testing purposes I even changed the default ("*") Message Format\Message Encoding\MIME setting to "provide message body as plain text," and that, too, changed absolutely nothing. I've restarted all Exchange services and SMTP service after every change. I've been Googling and reading 'til my fingers and brain turned blue but can't find a solution/explanation. I thought these Exchange settings are supposed to override Outlook's settings. Um, help?