On Thu, 28 Oct 1999, Hans Matzen wrote:
> but imho message ids are only locally unique aren't they ?
No. They should be world-unique. RFC 822 says
4.6.1. MESSAGE-ID / RESENT-MESSAGE-ID
This field contains a unique identifier (the local-part
address unit) which refers to THIS version of THIS message.
The uniqueness of the message identifier is guaranteed by the
host which generates it. This identifier is intended to be
machine readable and not necessarily meaningful to humans. A
message identifier pertains to exactly one instantiation of a
particular message; subsequent revisions to the message should
each receive new message identifiers.
The revision of RFC822 (still in draft, AFAIK) says the same thing, and
also contains this sentence:
The "Message-ID:" field contains a single unique message identifier.
That is why message ids usually have the host name after the @. There
has been much discussion on various lists as to how to generate suitably
unique message ids when you don't have a unique host name available.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Government Policy: If it ain't broke, fix it till it is.
