[TriLUG] Problems with Sendmail

[Brian Weaver]

Guys & Gals,

I have a friend who is having some serious issues with Sendmail and
could use some help. I've tried to figure out the problem and I'm
stumpped for the most part. Google has provided only liimited
information and the one site that might have had information (experts
exchange) requires a pay for membership to view their solution. Below
is the message I received.

NOTE: I've sanatized the e-mail addresses and company information at
the request of the my friend.

==== Begin Forwared Message ====
Hey Brian,

    I am once again in Linux hell trying to figure out a problem we are
having with Sendmail.  We have made two changes at one time.  Introduced a
firewall (Cisco PIX) and are now using MXLogic email services for spam and
virus filtering outside our mail server.  Using MXlogic required us to
change our outside MX records to point to MXLogic and lock down port 25
inbound on the firewall to only accept connections from MXLogics servers.
We changed our Sendmail config to define a SMART_HOST for
outbound.mxlogic.net for the email outbound.

    Here's my problem.  When a person sends an email from an outside address
and it uses MDN for read receipt, the receipt notification hangs up in the
mail queue with a 451: Could Not Load Relay DRD error.  When I try to flush
the mail message and watch the logging, I have these statements:
Running /var/spool/mqueue/k22DhIVO006163 (sequence 1 of 1)

<someone at somewhere.com>... Connecting to outbound.mxlogic.net. via relay...

220 p03m115.mxlogic.net ESMTP mxl_mta-2.14.0-09 [2221697968.245882]; Thu, 02
Mar 2006 13:08:49 -0700 (MST); NO UCE, OUTBOUND

>>> EHLO mail.somecompany.com

250-p03m115.mxlogic.net

250-SIZE 0

250-STARTTLS

250-SUBMITTER

250 PIPELINING

>>> STARTTLS

220 Ready to start TLS negotiation

>>> EHLO mail.somecompany.com

250-p03m115.mxlogic.net

250-SIZE 0

250-STARTTLS

250-SUBMITTER

250 PIPELINING

>>> MAIL From:<> SIZE=2339

451 Could not load relay DRD

<someone at somewhere.com>... Deferred: 451 Could not load relay DRD

Closing connection to outbound.mxlogic.net.

>>> QUIT

221 p03m115.mxlogic.net Service closing transmission channel

==== End Forwarded Message =====

Now my friend noticed the line right before the '451 Could not load
relay DRD' and thought it odd. Myself I find it odd too because there
should be an address in the 'MAIL FROM:<> SIZE=2339' line.

I can get more information if anyone has any idea on how to fix this.
It's my understanding that this only affects messages in response to a
"Receipt Required" setting on outlook mail. I.E. Someone sends a user
at 'somecompany' a message, when they read it outlook automatically
sends a reply saying that the user has received/read the message.

Oh, one final thing of note. Apparently in the Queue file for sendmail
the following lines appear:

${daemon_flags}

${if_addr}127.0.0.1

S<>

MDeferred: 451 Could not load relay DRD

Supposedly if the file is edited and an address is inserted in between
the '<>' on the line 'S<>' then sendmail will be able to send the
message without any errors.

Thanks

-Brian

--

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