On 8/20/10, Steffen Heil <lists@???> wrote: > This was probably meant and is fine.
> The address given by RCPT TO is also known as "envelope-from", which needs
> to be empty.
>
> If some server replied to such a mail with anything, there is something
> wrong on that side...
I guess so since not every sender creates the mail loop problem. Just
every few months, that situation arises with a local user over quota
at the same time they have a vacation autoreply then usually one
particular sender or another (totally random) will start responding to
bounces using the 'From' header.
Can't fix the other server so I guess I'll live with mangling the
'From' header on my side. :)