> ned+ietf@xxxxxxxxxxxxxxxxx <ned+ietf@xxxxxxxxxxxxxxxxx> wrote: > > > > The closest existing code is 5.4.4 Unable to route: > What's wrong with 5.1.2 and 5.1.8 ? > X.1.2 Bad destination system address > The destination system specified in the address does not exist > or is incapable of accepting mail. For Internet mail names, > this means the address portion to the right of the "@" is > invalid for mail. This code is only useful for permanent > failures. > X.1.8 Bad sender's system address > The sender's system specified in the address does not exist or > is incapable of accepting return mail. For domain names, this > means the address portion to the right of the "@" is invalid > for mail. Wrong group of codes. Those are status for mail systems to return, not the routing layer. Ned