Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!jarthur!ucivax!gateway From: JPALME@qz.qz.se (Jacob Palme QZ) Newsgroups: comp.protocols.iso.x400 Subject: Re: Is X.400 good for international mail? Message-ID: <584414*JPALME@QZ.qz.se> Date: 7 Jan 91 09:24:56 GMT References: <9101062017.AA11413@earth.touch.com> Lines: 29 Approved: usenet@ICS.UCI.EDU Autoforwarded: true > From: Tim Kehres > Subject: Re: Is X.400 good for international mail? > ------------------------------------------------------------ > In your message, you write: > > The Internet mail routers use so-called name-servers to translate > > a domain into a path. This means that the same path must be used > > for all names with the same domain. > > This is not entirely true. Intenet mail routers are supposed to check > for MX (Mail Exchange) records first rather than Address records for > mail routing. Associated with MX records are relative priorities, making > it possible to have multiple MX records for a given host or domain. It > is then up to the routing software to choose which path to use based > upon this data. What I meant was that Internet mailers normally choose the path by looking up the domains of the recipient in the name servers. X.400 mailers are supposed to look up the whole name of the recipient in the Directory System (X.500 system) in order to translate the name into a path. I have heard it argued that this is an advantage with the Internet way of handling mail, since the directory data bases need not be so large if they only list domains, and not the individual names of all users. On the other hand, it might be possible to define X.500 directory systems to use only the domains when translating a name into a delivery path.