Can Microsoft Exchange Server handle non-ASCII characters in domain names?

The Internet Engineering Task Force (IETF) has updated the Requests for Comments (RFCs) that govern permissible characters in DNS names. Therefore, names such as É and mø are now legal, assuming that your DNS client and server support them. Exchange and Microsoft Outlook, however, don't currently support such names. RFC 3490 ( explains how applications can convert non-ASCII characters to an ASCII representation, but at the time of this writing, Microsoft has no plans to modify Exchange or Outlook to do so.