Typical Cases of email server troubleshooting

Email server fault symptom description:

Email server A and email server B are set at the front-end. After the front-end receives the email, it is delivered to the mailbox in the backend server. After receiving the external email, the front-end cannot deliver the email to the backend mailbox, this results in a backlog of emails on the front-end server. It takes about 25 minutes for internal mail delivery to arrive.
 
By looking at the various services on the front and back end servers, we found that all services are normal. because they cannot be delivered to the backend servers, we first determined that the backend servers may have problems and decided to restart them.
 
It takes four minutes to restart the server. At this time, check the frontend queue and find that the service has been properly delivered to the backend server. The problem is resolved, which may be caused by an unexpected failure of the backend server service.
 
However, after five minutes of observation, we found that the problem still exists, and the external mail delivery is still stuck on the front-end server. As a result, we found the following symptoms:
The interval between Message Submitted to Advanced Queuing and Started Message Submission to Advanced Queue exceeds 10 minutes. The interval between Message Submitted to Categorizer and Message Categorized and Queued for Routing is nearly 10 minutes, based on this clue, search for information and obtain the following similar symptoms:
 
Http://www.microsoft.com/technet/prodtechnol/exchange/ZH-CN/Guides/E2k3TransnRouting/18682a71-ba92-42ec-9a54-8514d607c522.mspx? Mfr = true

Delayed Email Delivery due to a problem with the Global Catalog server
A Global Catalog problem may cause a delay in mail delivery. In this case, NDR is generated to notify the sender of this delay. You can use the mail tracking center to diagnose these problems. The following example shows the data collected from the mail tracking center:
6/22/2001 PM Tracked message history on server CONTOSO-MSG-01
6/22/2001 :54 pm smtp Store Driver: Message Submitted from Store
6/22/2001 :54 pm smtp: Message Submitted to Advanced Queuing
6/22/2001 :54 pm smtp: Started Message Submission to Advanced Queue
6/22/2001 :54 pm smtp: Message Submitted to Categorizer
6/22/2001 4:24 pm smtp: Started Outbound Transfer of Message
6/22/2001 4:24 PM Message transferred out to FOURTHCOFFEE. COM through SMTP
6/22/2001 4:24 pm smtp: Message Submitted to Advanced Queuing
6/22/2001 4:24 pm smtp: Started Message Submission to Advanced Queue
6/22/2001 4:24 pm smtp: Message Submitted to Categorizer
6/22/2001 4:24 pm smtp: Started Outbound Transfer of Message
6/22/2001 4:24 PM Message transferred out to FOURTHCOFFEE. COM through SMTP
6/22/2001 4: 24 pm smtp Store Driver: Message Delivered Locally to Store
In the above example, it should be noted that the mail was delayed for 30 minutes in the mail classification program, and then the outgoing transmission was started and finally delivered. In these cases, you should run the Nltest tool to determine which Global Catalog server Exchange uses. The procedure is described in "use mobile mail tool to move recipients to Active Directory" before this topic. Then, investigate the Global Catalog server involved. The following are common problems with the Global Catalog server:
• The Global Catalog server is overloaded or overloaded.
• Performance problems occur on the Global Catalog server.
• Insufficient memory.
• Insufficient disk space.
• Temporary network problems occur between Exchange 2000 and the Global Catalog server.
• For Exchange servers that use the same Global Catalog server, the recommended ratio of Exchange processor to Global Catalog server processor is four to one ).

Key points:

Email tracking logs may be misleading. For example, if the Global Catalog server works normally and the mail classification program works normally, but the remote SMTP server is unavailable for up to thirty minutes, the Mail Tracking log may be similar to the sample log shown above. In addition, if the mail must be delivered locally and the Exchange storage is slow, the Mail Tracking log shows that there is a large time difference between "the mail has been submitted to the mail classification program" and "the mail has been delivered to local storage.
When recreating a problem, use system monitor logs from the Global Catalog server. This helps you diagnose these problems. You can solve these problems by using the Global Catalog server again. To solve these problems, you can specify a Global Catalog server for each Exchange Server.

Note:

We recommend that you manually configure the Global Catalog server only when troubleshooting. After you manually configure the Global Catalog server, if a server is unavailable, Exchange cannot detect it.
For more information, see How to specify a Global Catalog server.
For more information about DSAccess, see article 250570 in the Microsoft Knowledge Base: "XCON: Directory Service Server Detection and DSAccess Usage ".
ExchOwningPFTreeBL: CN = Public Information Store (PFREP55), CN = First Storage Group, CN = InformationStore, CN = PFREP55, CN = Servers, CN = FourthCoffee, CN = Administrative Groups, CN = Lake District, CN = Microsoft Exchange, CN = Services, CN = Configuration, DC = cumbria, DC = extest, DC = microsoft, DC = com;
CN = Public Folder Store (PFREP57), CN = First Storage Group, CN = InformationStore, CN = PFREP57, CN = Servers, CN = Coniston, CN = Administrative Groups, CN = Lake District, CN = Microsoft Exchange, CN = Services, CN = Configuration, DC = cumbria, DC = example, DC = microsoft, DC = com;
CN = Public Information Store (PFREP56), CN = First Storage Group, CN = InformationStore, CN = PFREP56, CN = Servers, CN = Coniston, CN = Administrative Groups, CN = Lake District, CN = Microsoft Exchange, CN = Services, CN = Configuration, DC = cumbria, DC = example, DC = microsoft, DC = com;

The purple word has the same symptoms as ours. Therefore, based on this result, we query the two email servers to obtain the account GC and run the command
NLTEST/DSGETDC: suzsoft.com/GC
The following information is displayed:
NLTEST/DSGETDC: suzsoft.com/GC
DC: \ w2kdc1.suzsoft.com
Address: \ 10.0.15.11
Dom Guid: f4938c04-de3e-4db1-bbd6-b8a65eaeb77e
Dom Name: suzsoft.com
Forest Name: suzsoft.com
Dc Site Name: Default
Our Site Name: Default
Flags: pdc gc ds ldap kdc timeserv gtimeserv writable DNS_DC DNS_DOMAIN
DNS_FOREST CLOSE_SITE
The command completed successfully


NLTEST/DSGETDC: suzsoft.com/GC
DC: \ w2kdc2.suzsoft.com
Address: \ 10.0.15.12
Dom Guid: f4938c04-de3e-4db1-tt58-b8a666dwb07e
Dom Name: suzsoft.com
Forest Name: suzsoft.com
Dc Site Name: Default
Our Site Name: Default
Flags: pdc gc ds ldap kdc timeserv gtimeserv writable DNS_DC DNS_DOMAIN
DNS_FOREST CLOSE_SITE
The command completed successfully

It can be seen that the GC referenced by the two servers is different. Since this problem has not occurred before, we guess whether there is a problem with the synchronization of the two GC servers, as a result, GC data is not synchronized, And the referenced data of the email server cannot be matched, so the email cannot be transmitted. Therefore, we have done the following:
 
Corrected the default reference GC of the email server to ensure that the two email servers reference the same GC data. After the restart takes effect, the problem is solved.
 
Summary:
 
Because the EXCHANGE Server is very tightly integrated with the domain, when the mail server encounters a problem, it may be caused by a problem with the domain controller.
 
Appendix 1: How to specify a Global Catalog server
 
Http://www.microsoft.com/technet/prodtechnol/exchange/ZH-CN/Guides/E2k3TransnRouting/411e8bfd-6291-4bd0-bfd5-dad94220062e.mspx? Mfr = true
 
A Global Catalog problem may cause a delay in mail delivery. In this case, NDR is generated to notify the sender of this delay. You can use the mail tracking center to diagnose these problems.
The following are common problems with the Global Catalog server:
• The Global Catalog server is overloaded or overloaded.
• Performance problems occur on the Global Catalog server.
• Insufficient memory.
• Insufficient disk space.
• Temporary network problems occur between the Exchange 2000 Server and the Global Catalog Server.
• For Exchange servers that use the same Global Catalog server, the recommended ratio of Exchange processor to Global Catalog server processor is four to one ).

Key points:

Email tracking logs may be misleading. For example, if the Global Catalog server works normally and the mail classification program works normally, but the remote SMTP server is unavailable for up to thirty minutes, the Mail Tracking log may be similar to the sample log shown above. In addition, if the mail must be delivered locally and the Exchange storage is slow, the Mail Tracking log shows that there is a large time difference between "the mail has been submitted to the mail classification program" and "the mail has been delivered to local storage.
When recreating a problem, use system monitor logs from the Global Catalog server. This helps you diagnose these problems. You can solve these problems by using the Global Catalog server again. To solve these problems, you can specify a Global Catalog server for each Exchange Server.
Note:
We recommend that you manually configure the Global Catalog server only when troubleshooting. After you manually configure the Global Catalog server, if a server is unavailable, Exchange cannot detect it.
Before getting started
Before proceeding to the steps in this topic, please read the failure report email troubleshooting.
To perform this step, you must have the following permissions:
• Members of the local administrator group and members of the Group at the organization level who have applied the Exchange administrator role

Procedure
Specify the Global Directory Server
1. In Exchange system manager, expand server, right-click your Exchange server, and then click Properties ".
2. Click the "Directory Access" tab.
3. In "display", select "Global Catalog server ".
4. Clear the "Automatic Probe server" check box.
"Directory Access" tab
5. Click "add", and then select the Global Catalog server for which you want to troubleshoot. The selected server used as the Global Catalog server for the domain must exist in Active Directory, be accessible through LDAP port 3268, and be able to process requests from the Exchange Server in real time, and must have all enabled mail attributes of recipient objects.

The following example shows the data collected from the mail tracking center:
6/22/2001 PM Tracked message history on server CONTOSO-MSG-01
6/22/2001 :54 pm smtp Store Driver: Message Submitted from Store
6/22/2001 :54 pm smtp: Message Submitted to Advanced Queuing
6/22/2001 :54 pm smtp: Started Message Submission to Advanced Queue
6/22/2001 :54 pm smtp: Message Submitted to Categorizer
6/22/2001 4:24 pm smtp: Started Outbound Transfer of Message
6/22/2001 4:24 PM Message transferred out to FOURTHCOFFEE. COM through SMTP
6/22/2001 4:24 pm smtp: Message Submitted to Advanced Queuing
6/22/2001 4:24 pm smtp: Started Message Submission to Advanced Queue
6/22/2001 4:24 pm smtp: Message Submitted to Categorizer
6/22/2001 4:24 pm smtp: Started Outbound Transfer of Message
6/22/2001 4:24 PM Message transferred out to FOURTHCOFFEE. COM through SMTP
6/22/2001 4: 24 pm smtp Store Driver: Message Delivered Locally to Store
In the above example, it should be noted that the mail was delayed for 30 minutes in the mail classification program, and then the outgoing transmission was started and finally delivered. In these cases, you should run the Nltest tool to determine which Global Catalog server Exchange uses. The procedure described in the "use a mobile mailbox tool to move recipients to Active Directory" section in common scenarios where a non-delivery report is generated. Then, investigate the Global Catalog server involved.
For more information about DSAccess, see article 250570 in the Microsoft Knowledge Base: "XCON: Directory Service Server Detection and DSAccess Usage ).