Failue to deliver messages due to security policy (550 5.7.1) 1

[furtech]

Hello,

We recently changed ISPs which meant a DNS records update, we use NO-IP and I'm certain we have the correct MX record. We can receive emails and most emails are being sent out. However, a few uses have noticed problems with certain domains.

Below is a copy of the error message... Any ideas on what could be the problem?


<Begin>
Delivery has failed to these recipients or distribution lists:

<email address removed>
Your message wasn't delivered because of security policies. Microsoft Exchange will not try to redeliver this message for you. Please provide the following diagnostic text to your system administrator.

The following organization rejected your message: mail2.<domain removed>.com.

_____
Sent by Microsoft Exchange Server 2007

Diagnostic information for administrators:

Generating server: <mail server name removed>

<email address removed>
mail2.<domain removed>.com #550 5.7.1 Client host rejected: cannot find your hostname, [<IP address removed>] ##
<End>

Thanks.


---------------------------------------
Matthew Collins

http://www.furtech.net

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[markdmac]

You need to set up an RDNS entry in public DNS that resolves your public IP to the host name of your server.

I hope you find this post helpful.

Regards,

Mark

Check out my scripting solutions at

http://www.thespidersparlor.com/vbscript

Work SMARTER not HARDER. The Spider's Parlor's Admin Script Pack is a collection of Administrative scripts designed to make IT Administration easier! Save time, get more work done, get the Admin Script Pack.

 

[furtech]

Thanks, should the RDNS be setup by the ISP?

---------------------------------------
Matthew Collins

http://www.furtech.net

---------------------------------------

 

[alfa2008]

Yes, ISP has to do it for you.

 

[markdmac]

Some ISP control panels offer you the ability to do it yourself. Check there first.

I hope you find this post helpful.

Regards,

Mark

Check out my scripting solutions at

http://www.thespidersparlor.com/vbscript

Work SMARTER not HARDER. The Spider's Parlor's Admin Script Pack is a collection of Administrative scripts designed to make IT Administration easier! Save time, get more work done, get the Admin Script Pack.