Whenever you get a problem in Exchange 2010 I guarantee that one of the
logs will provide vital clues to find the root cause. The hidden
agenda of this page is to
open your eyes to the numerous types of Exchange logs, and show you where to find them.
Microsoft is not perfect. However, I have always felt that from
the earliest Windows operating systems Microsoft provides lots of troubleshooting information
in their logs.
The reason that Exchange 2010 has so many logs in so many locations is simply because it has
so many components. On an Exchange server there are database logs for the mailstore, Windows 2008
application logs, SMTP protocol logs and virus logs. If that is not
enough, you can create your own performance logs.
Unfortunately there is no central location to view all these Exchange
related logs, therefore you have to start exploring locations such as the \exchsrvr folder, Event
Viewer and even the root of the C:\ or D:\ drive.
Whenever I get an email problem, I try and make myself look in the Event Viewer earlier, rather than later in the troubleshooting
process. Therefore in the case of Exchange 2010, I urge you to begin with the Application
Log. People often say 'finding the problem is like looking for a needle in a haystack'. My reply is: ' master Event Viewer's Filter '. Click on the View Menu, Filter and select one of these from the Event Source box.
Exchange also has two setup logs to troubleshoot install programs. These files are created in the root of the drive where the Exchange 2010 binaries are installed. For example look
in C:\ or D:\. These files give reasons why setup failed.
Perhaps Exchange 2010 could not extend the schema, or encountered problems overwriting priv1.edb in the MDBDATA folder. I once used the progress log
to solve a replication problem when migrating from Exchange 5.5.
Guy Recommends:
The SolarWinds Exchange Monitor
Here is a
free tool to monitor your Exchange Server. Download and
install the utility, then inspect your mail queues, monitor the Exchange
server's memory, confirm there is enough disk space and check the CPU
utilization. This is the real deal - there is no catch. SolarWinds
provides this fully-functioning product for free, as part of their commitment to
supporting the network management community.
In Exchange 2010 server, SMTP (Simple Mail Transport Protocol) has
several shades of meaning. On this page I
use the word SMTP in the context of understanding logs. These SMTP logs contain records of each server's email conversations. However, bear in mind that the acronym SMTP has other connotations, for
example, SMTP Virtual Server, the SMTP service in IIS and SMTP routing
connections.
Let us
take the situation where one server is collecting email, but only intermittently. We would like to
investigate the SMTP conversation between two Exchange 2010 servers
and thus discover the cause of the problem. Here is a classic job for SMTP protocol logging.
There are two ways of
locating the diagram opposite, either visit IIS, or launch the Exchange System Manager, navigate to
Protocols folder and click on the SMTP server icon.
Choice of SMTP Log Formats
You have 4 methods for collecting SMTP conversations:
W3C Extended Log File Format
NCSA Common Log File Format
ODBC Logging
Microsoft IIS Log File Format
The default log format is W3C Extended. This format is the best way to get started with SMTP logging. However,
when you need more extensive search capabilities, such as investigating a
SQL
database, then select ODBC Logging.
The W3C format is my favourite SMTP logging method. In particular, I like the flexibility provided by extended properties on the advanced tab.
Here is the output of log where I chose to record the client IP, the SMTP method, and the reply code or sc-status.
#Software: Internet Information Services 6.0 #Version: 1.0 #Date: 2006-02-03
15:18:43 #Fields: time c-ip cs-method cs-uri-stem sc-status
Explanation:
#Software: IIS v 6.0 (Probably
from a Windows Server 2010)
#Version: 1.0 Means W3C Extended log format (Not ODBC)
#Date: Probably USA day month format. #Fields: As the name field suggests the column heading for the data recorded. Example, cs-uri-stem means the
resource
requested.
Understanding the SMTP codes
s- means server, whereas sc- means server to client. For example sc-bytes means the number of bytes sent by the server. c- I expect that you have
already guessed,
c- means client.
Mail Transfer conversation
#Fields: time c-ip cs-method sc-status
15:18:11 10.2.1.10 HELO 250
15:18:13 10.2.1.10 MAIL 250
15:18:19 10.2.1.10 RCPT
250 15:18:29 10.2.1.10 DATA 250
15:18:31 10.2.1.10 QUIT 240
Possible SMTP methods found under
cs-method: HELO, MAIL, RCPT, DATA and QUIT.
sc-status value of 250. Server to client transactions, which return a value 250, means O.K. (421 would mean service not available, or 554 would mean transaction failed).
Finding the location of the SMTP logs is not trivial. Whereas many programs output their events to the Application log, SMTP Logs are to be found under the "%windir%\system32\logfiles\SMTPSVC1*. Typically, you get a one log for each day, so double click
the file that you are interested in and notepad will open the log and display the data.
All W3C Extended Log File Format files begin with ex, for example exyyddmm.log
* Corrected by Juha (Guy thought it was
%windir%\system32\logfiles\W3SVC1)
If you click Start (Menu), Run, Logfiles (Type), now you should see the Windows Explorer open the correct directory
to find your SMTP logs.
What to look out for Open Relaying - Symptoms your server is sending mail that you do not recognise to an external server. Moreover it's not just one email but a whole load of possible spam messages.
Guy Recommends: SolarWinds' Log & Event Management Tool
LEM will alert you to problems such as when a key
application on a particular server is unavailable. It can also
detect when services have stopped, or if there is a
network latency problem. Perhaps this log and event management
tool's most interesting ability is to take corrective action, for
example by
restarting services, or isolating the source of a maleware attack.
Yet perhaps the killer reason why people
use LEM is for its
compliance capability, with a little help from you, it will ensure that your organization complies with industry
standards such as CISP or FERPA. LEM is a really smart
application that can make correlations between data in different logs,
then use its built-in logic to take corrective action, to restart services,
or thwart potential security breaches.
This page is designed to help you understand SMTP logs. Exchange relies on IIS to provide protocol logging. Of the four formats available, W3C Extended Log File Format provides the greatest choice of output. ODBC logging is useful if you have a SQL
database and need to query a large amount of data. To check your SMTP logs, click Start (menu), run, logfiles.
When you are troubleshooting Exchange 2010, collect the evidence by going first to the event logs.
Also explore the variety of locations and types of logs that Exchange 2010 has to offer. Find out where
to turn the logs on, and discover how to interpret the output data.
If you like this page then please share it with your friends
Here is a
free tool to monitor your Exchange Server.
Download the utility, then inspect your mail queues, monitor Exchange server's
memory, confirm there is enough disk space and check the CPU utilization.
If you click Start (Menu), Run, Logfiles (Type), now you should see the Windows Explorer open the correct directory
to find your SMTP logs.
