Seeing authentication failures regularly in maillog

[Philip Prindeville]

I'm seeing transactions like the following being logged in maillog:

Nov 17 06:26:46 mail sendmail[23544]: NOQUEUE: connect from 
localhost.localdomain [127.0.0.1]
Nov 17 06:26:46 mail sendmail[23544]: AUTH: available mech=DIGEST-MD5 
ANONYMOUS CRAM-MD5, allowed mech=EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 
LOGIN PLAIN
Nov 17 06:26:46 mail sendmail[23544]: jAHBQkxI023544: Milter: no active 
filter
Nov 17 06:26:46 mail sendmail[23544]: STARTTLS=server, 
relay=localhost.localdomain [127.0.0.1], version=TLSv1/SSLv3, verify=NO, 
cipher=DHE-RSA-AES256-SHA, bits=256/256
Nov 17 06:26:46 mail sendmail[23544]: STARTTLS=server, cert-subject=, 
cert-issuer=, verifymsg=ok
Nov 17 06:26:46 mail sendmail[23544]: AUTH: available mech=LOGIN 
DIGEST-MD5 PLAIN ANONYMOUS CRAM-MD5, allowed mech=EXTERNAL GSSAPI 
DIGEST-MD5 CRAM-MD5 LOGIN PLAIN
Nov 17 06:26:46 mail sendmail[23544]: ruleset=trust_auth, 
arg1=root at mail.redfish-solutions.com, relay=localhost.localdomain 
[127.0.0.1], reject=550 5.7.1 <root at mail.redfish-solutions.com>... not 
authenticated
Nov 17 06:26:46 mail sendmail[23544]: jAHBQkxJ023544: 
from=<root at mail.redfish-solutions.com>, size=2549, class=0, nrcpts=1, 
msgid=<200511171102.jAHB2IWk023430 at mail.redfish-solutions.com>, 
proto=ESMTP, daemon=MTA-v4, relay=localhost.localdomain [127.0.0.1]
Nov 17 06:26:46 mail sendmail[23545]: jAHBQkxJ023544: alias 
<root at mail.redfish-solutions.com> => philipp
Nov 17 06:26:46 mail sendmail[23430]: jAHB2IWk023430: to=root, 
ctladdr=root (0/0), delay=00:24:28, xdelay=00:00:00, mailer=relay, 
pri=32250, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent 
(jAHBQkxJ023544 Message accepted for delivery)
Nov 17 06:26:46 mail sendmail[23545]: jAHBQkxJ023544: to=philipp, 
delay=00:00:00, xdelay=00:00:00, mailer=cyrusv2, pri=32847, 
relay=localhost, dsn=2.0.0, stat=Sent
Nov 17 06:26:46 mail sendmail[23545]: jAHBQkxJ023544: done; 
delay=00:00:00, ntries=1


Any idea why that is?  Does it represent a failure?  Or is the message being
redelivered without authentication?

And why is authentication required on the loopback address?

-Philip