Hello,


> nginx doesn't attempt authentication against SMTP backends. You
> have to allow unauthenticated access from nginx on your SMTP
> backends.

ok, i thinking about this...
but there must be a error in my response from auth-server, because not postfix is rejecting mail but nginx is with internal error message.
postfix only says:
lost connection after XCLIENT from localhost[127.0.0.1]
what could be wrong? is there an additional header-line required?

Thanks,
Hajo