Stan Ryckman <[EMAIL PROTECTED]> writes:
> Well, the null envelope return address just means that there is nobody
> who cares if the message can be delivered; it can be silently trashed.
> It is you who CHOSE to examine mail that said "discard if
> undeliverable." Its use predates spamming by decades. True, the most
> COMMON use is to avoid "bounce loops."
If that's the true intention of the null envelope, then that's a *very*
bad idea, as a null envelope doesn't actually mean anything of the sort.
If a message with a null envelope bounces, that's a double-bounce, which
can often indicate a more serious misconfiguration, and some MTAs will
deliver the resulting double-bounce to the local postmaster. I find that
feature valuable.
Using a null envelope sender is not equivalent to saying that if the
message can't be delivered it should be silently trashed. If that's the
intention, you should use as the envelope sender an address that silently
discards all mail sent to it. Most stock sendmail configurations come
with an alias "nobody" that does this.
--
Russ Allbery ([EMAIL PROTECTED]) <URL:http://www.eyrie.org/~eagle/>
