XCON: Foreign MTA Rejects X.400 Messages (156716)

SYMPTOMS

An X.400 message sent from Microsoft Exchange Server to a foreign system might be rejected by the delivering Message Transfer Agent (MTA) if that MTA attempts to perform any actions on the originator and recipient X.500 directory names (DNs) contained within the message envelope.

CAUSE

In accordance with the 1988 X.400 standard, a field in the P1 is reserved for the X.500 DN name. This can be either Printable Character Set or Teletex. Microsoft Exchange uses a printable string but maintains non- printable characters in the DN. These non-printable characters can cause the rejection of messages at a foreign MTA.

MORE INFORMATION

The DNs are generated by Microsoft Exchange based upon certain configuration attributes. For example:

   o=MyOrg   <org>
   ou=My_site<site name>
   cn=RECIPIENTS<container name>
   cn=xxxxxxxx<user/display name?>

In the above example, an underscore in the site name will cause the problem. The encoded DN includes information identifying the attribute type (o, ou, cn, and so forth) and syntax. Microsoft Exchange specifies that the ou name syntax is PrintableString, but an underscore is not in the PrintableString character set (The X.500 standards state that the ou [and o] names can also be Teletext [T.61], which includes the underscore character).

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. This problem was corrected in the latest Microsoft Exchange Service Pack. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K