Re: Have message-ID set by my email server rather than by Message

[Lars-Johan Liman]

Hi rameiko87!

I know more about message standards then I know about the internals of
GNUS. That's why I come from that angle.

I'm beginning to understand your undelying problem, though, and I
realise it's a generic one that more people "ought to have". Am I right
in understanding it as "my host doesn't know its own hostname
(identity), so it's unable to create a useful Message-ID"?

If I "zoom out" and try to rephrase your problem as a generic question,
I come up with this:

"Which entity (i.e., which device) should be responsible for adding the
Message-ID header to a message composed on a device which has little or
no notion of its own host identity, and in those cases what should the
Message-ID be?"

Is that in line with the problem that you're having?

I happen to know the author of the mail specification RFC, and I'm
thinking about asking him for his thoughts. Would you object to that?

In the meantime, I'll provide this link in the hope that you can find
grains of help in this section of the mail message standard. The full
answer is not in there, but maybe you can make a better informed
decision of what to do if you read that.

https://datatracker.ietf.org/doc/html/rfc5322#section-3.6.4

                                Best regards,
                                  /Liman


rameiko87@posteo.net 2023-12-09 14:16 [+0000]:
> Dear Lars-Johan Liman,
> Thank you very much for your kind and exhaustive reply. I read in the
> Gnus manual:

>> If you have no idea what to insert for "yourmachine.yourdomain.tld",
>> you’ve got several choices. You can either ask your provider if he
>> allows you to use something like yourUserName.userfqdn.provider.net,
>> or you can use somethingUnique.yourdomain.tld if you own the domain
>> yourdomain.tld, or you can register at a service which gives private
>> users a FQDN for free.

> None of these apply to me. Then I read just below:

>> Finally you can tell Gnus not to generate a Message-ID for News at
>> all (and letting the server do the job) [...] you can also tell Gnus
>> not to generate Message-IDs for mail by saying:
>> //there's some code here//
>> , however some mail servers don’t generate proper Message-IDs, too,
>> so test if your Mail Server behaves correctly by sending yourself a
>> Mail and looking at the Message-ID.

> This is perfect! So I customized message-required-mail-headers. Now
> your explanation shows why I should not remove the mail headers, but
> still I wonder about the meaning of the lines cited above from the
> Gnus manual. And I also wonder what is the meaning of the variable
> message-required-mail-headers if it's essentially ignored by Message
> when I remove the Message-ID header from the list.

> Anyway now I'm back to the original problem where I don't know what to
> insert for Message-ID because the recommendations from the Gnus manual
> above don't apply, and also I can't understand how Message generates
> the portion which comes before the at-sign...

> And by the way, the standard for me would be
> fedora.mail-host-address-is-not-set . Is this even a fully qualified
> domain name, without extension? And how would I set mail host address?
> Because I can only find the variable mail-host-address which is set to
> system-name, which is fedora. Therefore I would expect the Message-ID
> to be fsfxxxxxxx@fedora
> (which by the way I think would miss the extension). If I set
> mail-host-address manually to fedora.ext, would Message-ID then be
> fsfxxxxxxx@fedora.ext? Then why don't they say
> mail-host-extension-is-not-set rather than
> mail-host-address-is-not-set in the default Message-ID when the
> mail-host-address *is* set but has no extension? So much confusion.

> On 09.12.2023 08:03, Lars-Johan Liman wrote:
>> Hi!
>> Message-ID is one of the very few _mandatory_ header lines, so a
>> message
>> without one is not a valid RFC 5322 (the sucessor of RFC 822) message.
>> Therefore the message "must not/cannot" leave your computer without
>> one.
>> It has to be set on the computer if it's being shipped by a
>> mail-related
>> protocol ((E)SMTP/LMTP/IMAP/POP[23]/...).
>> What you _can_ do (if I remember my sendmail.cf right, it's been a
>> few
>> years since I taught that course ... ;-) ) is to _modify_ the
>> Message-ID
>> header in your mail server. "If it looks like it's coming from the
>> computer, then modify Message-ID to look like ... (bla)". But I
>> wouldn't
>> recommend it. Message-ID is supposed to be set by the sending software
>> (the Mail User Agent (MUA)) and it's supposed to uniquely identify the
>> message across all messages in the world ... ever. Modifying it would
>> make it very difficult to trace and debug how the message traverses the
>> Internet (which includes your computer). You can probably also
>> influence
>> exactly how Emacs generates the Message-ID, but again, it's probably
>> not
>> a good idea to mess with that.
>> Can I ask what problem you see with having your Emacs generate the
>> Message-ID?
>>                              Best regards,
>>                                /Lars-Johan Liman