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

[rameiko87]

I made some progress.

> My original problem was that Emacs or one of the components which 
> intervene *locally* generate and introduce the Message-ID no matter the 
> value of message-required-mail-headers.

When message-required-mail-headers excludes Message-ID and 
message-generate-headers-first is true: then Message-ID doesn't appear 
when composing the email. Predictably sendmail adds it, but I still 
cannot explain why sendmail makes it correspond to the value of 
message-user-fqdn, which clearly only mentions "Message" in its name and 
id a variable defined in ‘message.el’ . How does sendmail know about 
it?!

> > "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?"

> My device composes the message before posteo.de transmits it. What is 
> my authority to use the formula xxxx@posteo.de in the Message-ID, 
> especially because the mix of self-generated xxxx and official-looking 
> @posteo.de looks intellectually confusing. Think of physical post: the 
> post office will stamp the branch number and timestamp the envelope 
> when they accept my parcel. posteo.de are charged with transmitting my 
> email: it only sounds reasonable they would add the Message-ID, which 
> is essentially hostname plus timestamp. Now one could make the case for 
> the added freedom which comes with deciding the Message-ID of your own 
> emails: but if the host can overwrite this anyway, then the benefit of 
> the potential added privacy which comes from setting Message-ID at the 
> MUA level is not guaranteed, but the drawback of having possibly same 
> Message-ID's for different emails (sent through the same host or even 
> distinct hosts) is real.

(A) Ideally the host would then feed back the Message-ID together with 
confirmation that the email was accepted for delivery, and then if the 
email is being saved locally (FCC) the MUA would store the Message-ID in 
the email message. In practice, which is not ideal for the reasons 
explained above and in particular the inconvenience of storing (FCC) an 
email with Message-ID different from the one the host server might 
decide to assign by overwriting the locally-generated one, the first 
system handling the message will create the Message-ID and store the 
email (FCC) with that Message-ID as soon as the email is accepted for 
delivery. In this case the message-ID can be anything because everything 
is done locally, but I suppose would be good practice to make what comes 
before @ algorithmically generated by the MUA and what is after be the 
hostname.

To mitigate the big inconvenience of the recipient having a different 
Message-ID from the one the sender stored with the sent-email, it would 
be good if the server would confirm that it accepts the message for 
delivery AND that it will honor the Message-ID locally generated, and if 
not both conditions are verified then abort sending the email. I don't 
think this happens.

I wish that (A) were the way things worked.