Re: [EAI] UTF-8 in Message-IDs

[Julien ÉLIE <[e-mail]>]

Hi John,

> If someone asked my opinion about whether a gateway should mess
> with Message-IDs, I'd say "no, unless it is absolutely required
> by the systems on the other end".  But lots of people don't ask
> and even fewer listen.   Neither RFC 5321/5322 nor RFC 5536
> offer any reciprocal guarantees.

RFC 5536 defines a stricter subset than RFC 5322 for Message-IDs; they 
therefore need being checked.  I agree with your saying that they should 
not be modified if they have a valid syntax for the system on the other end.

According to RFC 5537:

3.10.2.  Duties of an Incoming Gateway

    If there is a message identifier that fills a role similar to that of
    the Message-ID header field in news, it SHOULD be used in the
    formation of the message identifier of the news article, perhaps with
    transformations required to meet the uniqueness requirement of
    Netnews and with the removal of any comments so as to comply with the
    syntax in Section 3.1.3 of [RFC5536].  Such transformations SHOULD be
    designed so that two messages with the same identifier generate the
    same Message-ID header field.

       NOTE: Message identifiers play a central role in the prevention of
       duplicates, and their correct use by gateways will do much to
       prevent loops.  Netnews does, however, require that message
       identifiers be unique, and therefore message identifiers from
       other media may not be suitable for use without modification.  A
       balance must be struck by the gateway between preserving
       information used to prevent loops and generating unique message
       identifiers.

-- 
Julien ÉLIE

« Rien, ce n'est pas rien ! La preuve, c'est que l'on peut le
   soustraire. Exemple : rien moins rien = moins que rien ! »
   (Raymond Devos)