X.400 Email Format
X.400 email addresses are an alternative to SMTP email addresses. They are often referred to as originator/recipient addresses [OR]. Where a SMTP email address may be in the format:
. . . an X.400 email address will be in this form:
John Smith <"c=US/o=Acme/ou=corp/s=Smith/g=john">
These are common X.400 fields:
surName (S) givenName (G) initials (I*) (Zero or more) generationQualifier (GQ) OrganizationalUnits (OU1 OU2 OU3 OU4) OrganizationName (O) PrivateDomainName (PRMD) AdministrationDomainName (ADMD) CountryName (C)
The S, G, I, and GQ fields are sometimes combined in a PN (personal name) field. Alternatively a CN, common name, field may be used. For example, "cn=jsmith".
X.400 emails will be less common in emails after 2006. X.400 connector was not included with the Microsoft Exchange Server 2007.