Solved

Exchange 2010 Mail Relay Issue

Posted on 2012-03-21
9
855 Views
Last Modified: 2012-04-03
I have a pretty simple configuration with 2 Exchange 2010 servers (each at Rollup 6 SP1 running under Windows 2008 R2 in a single forest/domain) in a DAG configuration.  They're in different subnets with the primary server located in headquarters connected to the Internet and the secondary server in a branch office just used as a passive backup.  Before applying MS patches this weekend to the passive server, everything was working fine.  However after the patches, now whenever any mail reaches my primary server (on which all mailboxes are defined), the mail for some reason is being routed to the passive server and just sitting in the queue and going nowhere.  I can fix the problem by merely turning down the Exchange services on the passive server and everything works again.  What is possibly wrong and where do I go to troubleshoot this?

I've turned on logging and have looked through the logs but haven't seen anything that says there's a problem.  I ran two tests for sending outbound mail:
   
                       . Outlook - mail left my mailbox and shows up in the passive server queue
                       . test-mailflow  cmdlet from the active mail server which comes back with TestMailFlowResult: *Failure*

Again, after turning down the Exchange services on the secondary/passive server, mail goes out successfully on both tests.

I checked my Autodiscover under Outlook and it shows me connected to my primary server (I thought somehow I was being directed to the passive server but that isn't the case).  

The only other change I am aware of from this weekend is a change in the network architecture.  The passive server was in a subnet connected via a  T1 circuit back to headquarters but now it's connected via a VPN back to headquarters.  I don't think that should have anything to do with it.  

Thanks for any assistance!!!
0
Comment
Question by:ejefferson213
  • 5
  • 4
9 Comments
 
LVL 17

Accepted Solution

by:
Suraj earned 500 total points
ID: 37748592
This is by design. if you have DAG with hub role installed and also another dag member with hub role on it [be it passive] mails will go to the other hub.
That is one reason why Microsoft recommends to have Hub server on a different dedicated machine.
0
 
LVL 17

Expert Comment

by:Suraj
ID: 37748648
0
 

Author Comment

by:ejefferson213
ID: 37749179
VERY interesting!  Thanks for your reply.  I didn't mention that both my servers are essentially identical but you picked up on that; each has a mailbox and hub role.  Also I'm not using EdgeSync server, we're using our hub server for Internet based mail.  (I know it's not ideal but we're a small non-profit with not a lot of money for machines.)  So the mail I was referring to is mail to go to the Internet but based on the article you sent, it doesn't matter. Mail will still route through my "passive" DAG member.  

Therefore, I must have something configured improperly because it's not sending the mail back to the primary server that has access to the Internet.  The send connector on the hub transport of my secondary/passive server has the Source Server set to my primary server.  Since this secondary server has no Internet access, should I set the send connector of this server to use the Smart Host and point it to my primary server?
0
Optimizing Cloud Backup for Low Bandwidth

With cloud storage prices going down a growing number of SMBs start to use it for backup storage. Unfortunately, business data volume rarely fits the average Internet speed. This article provides an overview of main Internet speed challenges and reveals backup best practices.

 
LVL 17

Expert Comment

by:Suraj
ID: 37751753
Yes i know. its very interesting and most of the people get confused on mail flow on DAG.

Just add both the servers as source server on the send connector. Once done restart the transport server.
0
 

Author Comment

by:ejefferson213
ID: 37765673
Sorry for the delay.  I'll test this solution tomorrow morning and post back the results.  Thank you very much for your assistance.
0
 

Author Comment

by:ejefferson213
ID: 37770866
Hopefully I did this right.  I added both servers as the source server on the secondary Exchange server and specified the primary (internet facing) exchange server as the smarthost to the secondary server and then restarted the transport service on the secondary server. Unfortunately, mail submitted by an outlook client was received by the primary server and placed in the queue on the secondary server and never went out.  It had a delivery type of Smarthost connector delivery.  Is there something else I'm missing or didn't do?   Thank you!
0
 
LVL 17

Expert Comment

by:Suraj
ID: 37773003
so you mean you created a send connector between two hub servers ?
0
 

Author Comment

by:ejefferson213
ID: 37773902
I changed my send connector on my secondary server to indicate a smarthost was involved and pointed it to my primary server resulting in mail ending up in the secondary queue and going nowhere (unless I didn't wait long enough ~5 minutes).  Anyway, trying to be clever, I stopped the transport service and left all other services running and mail proceeded to go in and out of the primary server normally as before.  After restarting replication (mailbox copy) between the two servers, which succeeded, I was suddenly made aware that people were getting "Delivery Delayed" emails. Looking, I saw that messages were accumulating, this time in my primary server.  Having subjected my staff to issues before, I shutdown all email services on the secondary server and the mail in the queue went out.  So I'll leave these services down on my secondary server until I can get this fixed.
0
 

Author Closing Comment

by:ejefferson213
ID: 37800545
Thank you for explaining how mail flows with DAG; the reference to the article was very helpful.  Although I don't have it working yet, I'm sure I'll be able to get the right configuration in place to get this to work.  Thanks again.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

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

Suggested Solutions

This article explains in simple steps how to renew expiring Exchange Server Internal Transport Certificate.
This article aims to explain the working of CircularLogArchiver. This tool was designed to solve the buildup of log file in cases where systems do not support circular logging or where circular logging is not enabled
The basic steps you have just learned will be implemented in this video. The basic steps are shown to configure an Exchange DAG in a live working Exchange Server Environment and manage the same (Exchange Server 2010 Software is used in a Windows Ser…
how to add IIS SMTP to handle application/Scanner relays into office 365.

803 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