Exchange 2003 to 2007 mail in 'unreachable destination' queue

1. Windows Server 2003 R2 Standard SP2 w/ Exchange 2003 SP2
2. Windows Server 2008 Standard x64 SP2 w/ Exchange 2007 SP2

- Installation logs for Exchange 2007 show successful installation.

- Can send mail from Exchange 2007 to Exchange 2003 users

- Can send mail from Exchange 2007 to Internet

- Routing connectors were created for both sides during install; for my own sanity, I removed and recreated routing connectors via Exchange 2007 EMS

- Can telnet from Exchange 2003 to Exchange 2007; mail is delivered without error

- smart host is NOT configured in SMTP virtual directory

- ADSIEDIT shows correct permissions set for each administrative group (according to this link:

- Ran Best Practices and Troubleshooter on both servers; both tell me message are in the queue and that routes between them 'may not be available' (obvious??)

- Windows Firewall is disable on both servers

- No Event Viewer errors on either server

- Exchange 2007 has 2 receive connectors: Client and Default. One is configured for port 587 and other is configured for port 25. Permission for port 25: anon, exchange servers, legacy exchange servers

Any ideas where to go from here?
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Glen KnightCommented:
There are 3 reasons we see this.  

1st you have already eliminated by checking the Defaukt SMTP Virtual Server for a smarthost

2nd is the default outbound port on the Default SMTP Virtual Server

3rd Antivirus or SPAM software installed on the Exchange 2003 server is interfering with delivery.

The other possibility (so that's 4 really) is that the 2003 server cannot communicate with the 2007 server, check DNS, gateway configuration on the 2003 server.
Ping the 2007 server by IP, NETBIOS name & Fully Qualified Domain Name

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
network_admin3540Author Commented:
WOW! That was quick! Thanks!

- No av or spam apps installed on Exchange 2003 - only thing installed is backup exec 12.5 w/ exchange add-in.

- DNS and gateway config are correct (2007 and 2003)

- Ping results by IP: reply from IP

- Ping results by NETBIOS: reply from correct IP

- Ping results by FQDN: reply from correct IP
Glen KnightCommented:
Have you checked the outboundnport xonfiguration on the SMTP Virtual Server?
Problems using Powershell and Active Directory?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

Glen KnightCommented:
Out of interest did it work with the default routing group connector?
The one it creates automatically during installation should be correct.

I have to be honest I have never created it through Exchange 2007 so I don't know if 2003 will be able to use this?!
network_admin3540Author Commented:
TCP port: 25
network_admin3540Author Commented:
No, it did not work with the default routing group connector.
Glen KnightCommented:
What happens if you try a telnet test as per:

from each server to the other one.

Also try running the exchange best practice analyzer.

What does message tracking say?
network_admin3540Author Commented:
Telnet: message is received from 2003 to 2007

Telnet: message is received from 2007 to 2003

ran best practices analyzer. which test do you want to know about? i've ran them all! from both servers!

Message Tracker: SMTP:Message Submitted to Advanced Queueing
                              SMTP:Started Message Submission to Advanced Queue
                              SMTP:Message Submitted to Categorizer
                              SMTP:Message Categorized and Queued for Routing
                              SMTP:Message Routed and Queued for Remote Delivery
Glen KnightCommented:
If you look in the queues in the 2003 server which queue are they in and what does it say?

Do you receive an NDR or do the mails just disapear?
network_admin3540Author Commented:
In the messages with unreachable destination queue. NDR can be sent only if I manually do it. NDR says: This message was rejected due to the current administrative policy by the destination server.  Please retry at a later time.  If that fails, contact your system administrator.
            < #4.3.2>

Emails never leave the queue unless I manually delete them. The state of the messages is always queued.
Glen KnightCommented:
OK, that NDR is because you have generated it through the queue.

You haven't by any chance installed the SMTP service on the 2007 server? It's a long shot but it's all I have left :(

sometimes it's difficult to identify these problems without physically seeing your server.
network_admin3540Author Commented:
No SMTP :(

You tried :D
Glen KnightCommented:
You have ALL my ideas right there.

Let me ping a couple of other exchange experts to see if they can help
network_admin3540Author Commented:
new information from mail troubleshooting assistant:

- routing group member node not connected to master *NOTE* doubled checked that and set as master is checked for server 2003

-metabase entry with multiple corresponding GUIDs

-connector contained in link state information not found in directory

-routing group with a major version of zero
network_admin3540Author Commented:

Removed and recreated routing group connectors via EMS four times; restarting the Exchange 2003 server after each removal and creation. After the fourth time, it worked. ..... Never did get any errors in event viewer from exchange 2003 regarding the issue.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.