All mail sent to hotmail/ accounts unsuccessfully delivery

All internal network users on our Exchange Server are unable to send email to hotmail or msn accounts.  Our Exchange logs show successful sends.  This is the error that we receive:

Delivery has failed to these recipients or distribution lists:
An error occurred while trying to deliver this message to the recipient's e-mail address. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message, or provide the following diagnostic text to your system administrator.

The following organization rejected your message:


Sent by Microsoft Exchange Server 2007

Diagnostic information for administrators:

Generating server: servername #550 SC-002 Mail rejected by Windows Live Hotmail for policy reasons. The mail server IP connecting to Windows Live Hotmail has exhibited namespace mining behavior. If you are not an email/network admin please contact your E-mail/Internet Service Provider for help. Email/network admins, please visit for email delivery information and support ##

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There are a number of possible reasons for this behavior.  Since it's Hotmail, some of the possibilities that first come to mind are that DNS is incorrectly configured for your domain.  Confirm that reverse record (PTR) and the SPF record for your mail server exist and are correct.  

The best place to start, to check the DNS config for your domain is to run a full DNS Report here:  Just enter your domain name in the DNSreport box and run the report.  
Well, the reason your mail isn't being delivered is because hotmail is bouncing it.  I suspect this is because your mail server does not have correct Reverse DNS - can you confirm your DNS details for the server and I'll check it out further for you.
PROJHOPEAuthor Commented:
mdcsea: The DNS information appears correct.  The DNS report showed no problems other than a Postmaster tweak.

Haddion: Here is the DNS information:       name =       name =
Those answers are from me at home and also from UUNet public DNS server:
# nslookup
Non-authoritative answer:       name =
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There seems to be some confusion about the SPF record and your outbound mail servers (based on the DNSreport).

Your MX Records:

9 [TTL=5400] IP= [TTL=5400] [US]
20 [TTL=5400] IP= [TTL=5400] [US]

and your reverse DNS: [TTL=21600] [TTL=21600]

are both correct but the SPF record contains the following:

"v=spf1 ~all" [TTL=5400]

The servers listed here are:

none of these match your listed mail server IPs.  Essentially, the SFP record says that these three are the best servers to allow mail from.  You do have the entry "~all" but by default, this results in a SOFTFAIL result.  See these results:

SPF string used: v=spf1 ~all.
Processing SPF string: v=spf1 ~all.
Testing '' on IP=, target domain, CIDR 32, default=PASS.  No match.
Testing '' on IP=, target domain, CIDR 32, default=PASS.  No match.
Testing '' on IP=, target domain, CIDR 32, default=PASS.  No match.
Testing 'all' on IP=, target domain, CIDR 32, default=SOFTFAIL.  MATCH!


Possible Results:
Pass - This IP is authorized to send E-mail from this domain.
Fail - This IP is not authorized to send E-mail from this domain
SoftFail - This IP probably is not authorized to send E-mail from this domain, but the domain owners are not certain
Neutral - The domain does not know if the IP is allowed to send E-mail or not.
TempError - A temporary error occurred. The E-mail should be retried later.
PermError - A permanent error was encountered. The E-mail should be rejected.
None - No SPF record was found. It cannot be determined if the IP is allowed to send E-mail from this domain.
Since Hotmail does test the SPF record, your mails are probably being rejected because of the incorrect SPF.  Fix that up, allow it to propagate, and try again.

PROJHOPEAuthor Commented:
We have found that Hotmail feels that our email blasts are unsolicited.  We filled out a form from Microsoft to note our domain and mail IP addresses so it can take us off some blacklist...

Our users now are not having any problems we haven't adjusted anything on the Exchange server.
Who would have guessed - censorship rather than a real, functional, content-based spam filter solution.

Glad you got it working.  Might want to look at that SPF record anyway.

Thanks for letting us know.

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