Re: Who sets Sender:?

[Stainless Steel Rat <ratinox@peorth.gweep.net>]

* prj@po.cwru.edu (Paul Jarc)  on Tue, 21 May 2002
| Is the MUA supposed to be able to determine when Sender is needed?

If the user fails to create a Sender header when it is required then the
MUA needs to be able to do so.  In many (most?) cases the MUA must guess
because it cannot read the minds of the originator or sender.

| That criterion is satisfied equally well by either of our definitions.

Thus does not invalidate either of them.

| > and that an attempt has been made at getting the address correct if the
| > user has not done so himself.
| I can't find that criterion in RFC 2822.  Can you point it out?

Definition of addr-spec plus requirements of RFC 2821 and the other
protocols involved in mail handling.

| Even assuming this criterion, the MUA is extremely limited in its
| ability to construct a correct address.

This is true, however...

| user@hostname is often not a working address - I'd say it's wrong more
| often than right.

... if your site is configured properly, with a wildcard MX record for your
entire (sub)domain pointing to your site's mail server, and aliases or
mailer tables for mapping your users' login names to mailboxes, then
user@hostname will always be a working address.

| It seems to me that even for an MUA that wants to satisfy your position,
| it cannot do any better, on average, than leaving From and Sender
| entirely to the user.

The MUA cannot do it alone.  It needs help.  I have always stood by that
statement.  A properly configured site will have the resources in place so
that the MUA can guess correctly, or so that its guesses are always
correct.

[...]
| Yes, but you also (seem to) take the extra step of claiming that RFC
| 2822 demands this of you.  I'm not saying that you shouldn't configure
| your network that way, or that RFC 2822 claims that you shouldn't.
| I'm saying that RFC 2822 *doesn't* say that you *should*; it is silent
| on this issue.

Because site configuration is outside of the scope of RFC 2822.  So is Gnus
configuration.  What RFC 2822 demands is that mail messages be formatted
correctly.  Your solution, leaving the site broken and changing Gnus'
default behaviour, may cause Gnus to construct illegal headers.  My
solution, fixing the site and leaving Gnus alone, will never cause Gnus to
create illegal headers.  Your solution addresses a symptom of a problem and
may create another problem.  My solution addresses the problem and prevents
other problems.

-- 
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