Re: Message-ID

[Tibor Simko <tibor.simko@cern.ch>]

>>>>> "FW" == Florian Weimer <fw@cygnus.stuttgart.netsurf.de> writes:

    FW> You don't need to have a DNS entry for the FQDN, but it's
    FW> better if there's an MX record (for mail delivery).  [...] Of
    FW> course, the FQDN must be from a name space under your control,
    FW> otherwise you can't guarantee the uniqness of the message IDs
    FW> (which is required for news articles).

What about the following situation.  I'm using PPP with dynamic IP.
While offline I'm posting to a local queue which is flushed once the
PPP connection is on.

  * stage #1: At the moment of posting, FQDN is junk-name.isp.com
    since PPP is off.  No DNS entry exists for junk-name.isp.com.  It
    seems impossible to assure the uniqueness of Message-ID since
    someone may very well choose the very same junk-name, post at the
    very same time, using the very same uid, MUA, etc, etc.

  * stage #2: At the moment of sending the message to ISP, FQDN is
    dynamic-name-isp-gives-me.isp.com, which is a DNS-happy name.
    Good, but it is too late to create Message-ID since the post has
    already been queued before.  Since Message-ID attribution already
    happened, it does not seem to be a good idea to rewrite it with
    the new hostname, for several reasons; e.g. someone could have
    used it while I typed my message off-line so we may find the same
    uniqueness problem as described above.

Should the Message-ID creation be left completely to the ISP level and
not dealt with locally at all, neither by MUA nor MTA?

Tibor
-- 
Premature optimization is the root of all evil.  --Donald E Knuth