##  TrustedAuthservIDs string
##      default HOSTNAME
##
##  Specifies one or more "authserv-id" values to trust as relaying true
##  upstream DKIM and SPF results.  The default is to use the name of
##  the MTA processing the message.  To specify a list, separate each entry
##  with a comma.  The key word "HOSTNAME" will be replaced by the name of
##  the host running the filter as reported by the gethostname(3) function.
#
# TrustedAuthservIDs HOSTNAME

<-- 220 mx.example.com ESMTP Postfix (Debian/GNU)
--> HELO evil.example.net
<-- 250 mx.example.com
--> MAIL FROM:<someone.from@evil.example.net>
<-- 250 2.1.0 Ok
--> RCPT TO:<user@example.com>
<-- 250 2.1.5 Ok
--> DATA
<-- 354 End data with <CR><LF>.<CR><LF>
--> Authentication-Results: mx.example.com; spf=pass
--> Authentication-Results: mx.example.com;
-->         dkim=pass (1024-bit key; unprotected) header.d=example.com header.i=@example.com;
--> From: <user@example.com>
--> To: <user@example.com>
--> Subject: forged Authentication-Results: mx.example.com;

Authentication-Results: mx.example.com; spf=pass (mailfrom) smtp.mailfrom=evil.example.net ...
Authentication-Results: mx.example.com; dmarc=pass (p=reject dis=none) header.from=example.com
Received: from smtp.evil.example.net (evil.example.net [198.51.100.80])
    by mx.example.com (Postfix) with SMTP id D4AC64048A
    for <user@example.com>;