Julian Mehnle wrote:
> Kris Deugau wrote:
> > OK, I think I've thought of a sort of a counter-example:
> > [...]
> > I'm sending "from" myfriendsdomain.com's server,
> > but I don't have an account there.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > I do, however, have an account
> > myaccount@mydomain.com on
> > my own server- to which I want all replies/bounces/etc to go to.
> > --------
>
> Why don't you use <myfriend@myfriendsdomain.com> as the envelope-from
> and <myaccount@mydomain.com> as the "From:" header field? Replies
> will go to <myaccount@mydomain.com>
This is OK, and proper...
> , while bounces will go to <myfriend@myfriendsdomain.com>.
But this is bad. My friend will get a bounce for a (possibly personal)
message from me to a third party, which he supposedly has no interest in
seeing. About as bad as using the nonexistent
nullaccount@myfriendsdomain.com.
I wouldn't see the postmaster notification in either case because no
email address actually associated with me personally was involved in
sending my original message, except in "user-generated" headers that
SMTP systems are, by design, supposed to ignore.
> If your friend's server is configured correctly, it won't send
> out-of-band bounces (bounces as stand-alone messages, instead of a
> bounce reply code in the SMTP dialog) to foreign (non-local) servers
> anyway (to mitigate joe jobs on innocent bystanders whose address was
> used as some spam's envelope-from).
*shrug* If it's running any reaasonably recent Linux-based SMTP service,
for the simplest case of "all local users are full local accounts, for
all domains accepted as local", it will generate any such rejections at
SMTP time, and most others as well. It would NOT blindly relay mail
"from" myfriendsdomain.com.
For example:
Case #1:
I send a message to friend@someotherdomain.com, while at this LAN
party. I use an SMTP envelope address of myaccount@mydomain.com.
I mistype the destination address, so within 5-10 minutes or so, there
is a postmaster notification (generated on the server hosting
myfriendsdomain.com), telling me that the message couldn't be delivered
because the recipient doesn't exist. OK, no problem; I can see clearly
that I've mistyped something, and I can resend the message to the
correct destination. No problem.
Case #2:
I send a message to friend@someotherdomain.com, while at this LAN
party. I use a (nonexistent!) SMTP envelope address of
myaccount@myfriendsdomain.com.
I mistype the destination address, but because the SMTP return address
is local, the server tries to deliver to that account. Since that
doesn't exist, it bounces again to postmaster@myfriendsdomain.com. I
receive no indication that the message was *not* sucessfully (and
properly) passed on to its intended destination, so three days later
when talking face-to-face with friend@someotherdomain.com, I get a
little confused that he didn't get the email I sent three days earlier.
Case #3:
I send a message to friend@someotherdomain.com, while at this LAN
party. I use a (nonexistent!) SMTP envelope address of
myfriend@myfriendsdomain.com.
I mistype the destination address, but because my first friend's address
was used as the SMTP envelope sender, the bounce goes to his account. I
receive no indication that the message was *not* sucessfully (and
properly) passed on to its intended destination until he checks his
mail- or spam folder <g>, so three days later when talking face-to-face
with friend@someotherdomain.com, I get a little confused that he didn't
get the email I sent three days earlier.
IIRC the original question was answered to the satisfaction of the
person who asked it. Listing the servers allowed to send mail "from"
your domain, as a part of your DNS, makes perfect sense to me... "all"
you have to do is track down the IPs of those machines. <g>
-kgd
--
<erno> hm. I've lost a machine.. literally _lost_. it responds to
ping, it works completely, I just can't figure out where in my
apartment it is.