Subject: Re: bin/5039: change to vacation to support wider variety of mailers
To: Keith Moore <moore@cs.utk.edu>
From: Greg A. Woods <woods@most.weird.com>
List: netbsd-bugs
Date: 02/23/1998 22:33:19
[ On Mon, February 23, 1998 at 18:37:34 (-0500), Keith Moore wrote: ]
> Subject: Re: bin/5039: change to vacation to support wider variety of mailers 
>
> > >Description:
> > 
> > 	Vacation doesn't find the user's address in mail that's sent
> > 	without a 'To:' (or 'Cc:') header, and most importantly not in
> > 	mail that's been 'Bcc:'ed to the user.  However most mailers
> > 	do include the specific envelope address that resulted in the
> > 	delivery.  Unfortunately the header used to show this address
> > 	is not standard and several varieties exist.
> 
> 
> That's beside the point.  Vacation wants to check the header recipient
> addresses, (NOT the envelope recipient addresses), to determine
> whether the mail was personally addressed to the recipient, instead of
> just being list mail.  That way, it can respond to the personal mail
> and not respond to the list mail.

Mail sent by way of Bcc should be no less important than mail that is
Cc'ed or To'ed direclty to me.  It has absolutely *no* bearing
whatsoever on whether or not the mail was sent through a mailing list.

Since Bcc'ed mail need not contain the recipient's address in any normal
RFC header all that remains to be checked are the headers added by various

I fully realize that if vacation(1) does recognize the headers normally
used to represent the envelope-to address at final delivery then indeed
it will recognize mail sent to the user via lists or group aliases which
do not appear in the 'To' or 'Cc' headers.  However if list owners don't
have enough sense to put the appropriate 'Precedence' header in the mail
sent through their list then indeed they deserve every "vacation"
response they get back to the list.  This is not rocket science.

Personally I've always thought it terribly obnoxious and silly of
vacation(1) to think that it should check if the mail was really sent to
me or not.  Surely I'm smart enough only to invoke it via my own
~/.forward file!  If the mail arrives addressed to my mailbox then it is
to me and there's no valid algorithm that can determine from the
"destination" headers whether the mail was intended directly for me or
not.

My patch was indeed a subversive attempt to alleviate the most obnoxious
problem that results from its design without completely changing its
user interface.  Ideally I would rip out (or purposefully ignore) the
'-a alias' and 'login' arguments and have it pay attention *only* to the
'Precedence' header to determine if it needs to respond or not.  The
only other possible rule I would consider is to ignore messages with
'Resent-*' headers.  This is also reasonably clearly defined by RFC-822,
though not enough mailers follow this practice themselves....

Vacation(1) should have been fixed a half dozen years or so ago.  That
it still holds fast to the concepts of the 1980's is sad.

> (FWIW, automatic responses should indeed go to Return-Path and not
> Reply-To.)

True, but vacation(1) is really a MUA facility, not an MTA facility and
as such it should respond as an MUA (i.e. to the 'Reply-To'), not as an
MTA.  The RFCs are very clear on this point and nothing they say
prevents a user from having automated agents that respond on their
behalf.  One would normally expect such agents to respond as the user
would, *not* to the envelope sender address as an MTA must.  Such agents
are clearly not reporting delivery problems!

-- 
							Greg A. Woods

+1 416 443-1734      VE3TCP      <gwoods@acm.org>      <robohack!woods>
Planix, Inc. <woods@planix.com>; Secrets of the Weird <woods@weird.com>