Exchange 2007 - Messages stuck in queue - 451 4.4.0

Posted on 2008-10-22
Medium Priority
Last Modified: 2013-11-15
I've been configuring a Microsoft Exchange 2007 server and can currently send e-mail to most external domains. However, certain domains are rejecting e-mail with an error of:

 "451 4.4.0 Primary Target IP address responded with: "." Attempted failover to alternate host, but that did not succeed.  Either there are no alternate hosts, or delivery failed to alternate host".


 421-:  (DNS:NR)  http://postmaster.info.aol.com/errors/421dnsnr.html

I ran a DNS report and the "mail server greeting" section failed:

Failed Mailserver greeting - The server should have an A record which points to the mailserver for the hostname which is presented in the greeting:
   220 ****************************************************************************************

How can I change the A record so it points to the mail server for the hostname? Is that what is causing the messages to be stuck in the queue? I figured setting up an SPF record would remedy the problem but apparently it did not. Is there anything else I can try? I have a feeling reverse DNS may also have something to do with it. Help is appreciated!
Question by:qualityip
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3

Expert Comment

ID: 22778608
Is lambertgm.com your outgoing mail server, or an example of a mail server you're trying to send mail to?  I'm guessing it's your outbound mail server; you may just need an A record that connects "mail.lambertgm.com" with an IP address.

Author Comment

ID: 22778841
Lambertgm.com is the outgoing mail server. What's the best way to go about getting/setting that host A record?

Expert Comment

ID: 22779130
I think I mis-spoke above, the record you will need is a reverse DNS record.  Normal DNS starts with a server name and provides an IP address; reverse DNS starts with an IP address and provides a name.  The record you need will be created by your Internet service provider, you may have to jump through some hoops to find support reps who know about reverse DNS.  The IP address for this record will be the external IP of your mail server.
Optimize your web performance

What's in the eBook?
- Full list of reasons for poor performance
- Ultimate measures to speed things up
- Primary web monitoring types
- KPIs you should be monitoring in order to increase your ROI


Author Comment

ID: 22779226
I called the ISP and they said Network Solutions is handling the primary DNS and Network Solutions said they do not offer PTR records with their DNS services. Is there anything else I can try besides switching the primary DNS to the ISP?

Accepted Solution

Scott1201 earned 1500 total points
ID: 22780767
The primary DNS and reverse DNS would not be handled by the same company.  I've fought this battle before - the reverse DNS has to initiate with the ISP, because the resolution process starts from the IP address (owned by the ISP) rather than the name.  You should not need to move the primary DNS away from Network Solutions in order to get a reverse DNS record set up, but you might need to move up from first-level tech support at your ISP, or find a business support telephone number, before you run into someone who can help.

I do have clients who have reverse DNS through their ISP and primary DNS through Network Solutions or GoDaddy, so I know this can be done.

Author Comment

ID: 22787399
But of course, happens to be against AT&T policy to set up reverse DNS if they do not have the primary DNS. I really appreciate the help, any more suggestions?

Featured Post

Get real performance insights from real users

Key features:
- Total Pages Views and Load times
- Top Pages Viewed and Load Times
- Real Time Site Page Build Performance
- Users’ Browser and Platform Performance
- Geographic User Breakdown
- And more

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article I discuss my selections of the Top Four free Outlook OST File Viewers available. Open, view and read even damaged OST files by using these tools. They all provide a clear preview of all data such as emails, notes, tasks, calendars, e…
Curious about the latest ransomware attack? Check out our timeline of events surrounding the spread of this new virus along with tips on how to mitigate the damage.
To add imagery to an HTML email signature, you have two options available to you. You can either add a logo/image by embedding it directly into the signature or hosting it externally and linking to it. The vast majority of email clients display l…
This video demonstrates how to sync Microsoft Exchange Public Folders with smartphones using CodeTwo Exchange Sync and Exchange ActiveSync. To learn more about CodeTwo Exchange Sync and download the free trial, go to: http://www.codetwo.com/excha…
Suggested Courses

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question