Scheduled Maintenance Tasks
To keep your
Exchange organization running smoothly and to provide the level of
service that users demand, you need to perform regular, scheduled
maintenance tasks. You must define these tasks and the frequency with
which you perform them. Typically, you need to perform the following
reports and identify trends by using System Monitor, Microsoft
Operations Manager, or third-party utilities to capture performance
data. This data allows you to identify potential bottlenecks and, for
example, to estimate when a server must be upgraded.
protocol logs to track commands that are sent and received by SMTP,
NNTP, and HTTP virtual servers. Reviewing these logs can help you
troubleshoot messaging problems and identify potential problems.
HTTPMon to monitor your Outlook Web Access (OWA) servers and ensure
that client computers are not experiencing connection or performance
which users consume the most resources on your servers because this
information helps you configure and maintain your Exchange storage.
the Badmail folder to identify trends and prevent messages from
building up. Messages that cannot be delivered and cannot be returned to
the sender are sent to the Badmail folder. Over time, these messages
can accumulate and use up disk resources.
the postmaster mailbox, which is used for NDRs. You should define which
e-mail account is associated with the postmaster account and monitor
and respond to NDR messages when necessary.
Generating Reports and Identifying Trends
Your first task
when generating reports and identifying trends is to gather sufficient
information to establish a baseline for the performance of each Exchange
Server 2003 server. This information allows you to manage your servers
proactively and perform trend analysis and capacity planning. You should
create a baseline when you first deploy your server, and then
re-baseline whenever changes in hardware or usage occur.
To create a baseline
and then use deviations from that baseline to track trends and identify
potential problems, you must create procedures to monitor your Exchange
Server 2003 server. These procedures gather information about server
resources such as memory usage, processor utilization, hard disk space
utilization, disk performance, and network performance. In addition,
performance indicators specific to Exchange Server 2003 server, such as
Exchange store performance, message delivery rates, and message queue
problems, are included. Your system monitoring procedures should specify
the frequency of monitoring tasks, the baseline data to be captured,
and the appropriate procedures for managing any problems that may arise.
is implicit within system monitoring. System measurement parameters
include standards for the types of information measured, measurement
sampling rates, methods used to analyze data, data storage formats, and
enables you to allocate system resources to ensure that optimal system
performance is maintained as the system load increases. It is, however,
not sufficient to carry out capacity planning using current data, to
allocate the appropriate resources, and then to take no further action.
Capacity planning is a continuous process that requires that you
establish baselines for each service and then monitor all levels of
The Performance Console
Performance console is used to gather and display information about
performance objects and related counters. The console contains two
tools, or snap-ins: Performance Logs And Alerts and System Monitor.
The Performance Logs And
Alerts snap-in records and logs system activity over a period of time.
The tool enables you to collect data at regular intervals for the
counters you select. You can retain logs over extended periods of time
by storing data in a database created by Microsoft Access or Microsoft
SQL. If you store the data in a database, you can use the reporting
features of the database program to create reports that can be used to
assess overall performance and to perform trend analysis and capacity
planning. Performance Logs And Alerts can also be configured to generate
an alert if a counter value either exceeds or drops below a predefined
value. The alert, by default, will record an event in Event Viewer, but
you can configure it to send an administrative message or to initiate a
The System Monitor snap-in
lets you chart activity in real time. You also use it to display
information captured in log files by the Performance Logs And Alerts
snap-in as reports, graphs, or histograms. You can use System Monitor to
view server activity whenever server performance degrades. You can, for
example, analyze processor activity and queues and use this information
to isolate problems with specific components.
Configuring a Performance Console
configure the Performance console so that you can determine what is
normal system behavior and what modifications you can make to improve
performance. You need to know the average number of messages received
per user per day and the total number of messages downloaded in a
predefined period of time. You also need to know the frequency with
which users open folders.
If you have these
statistics, you can calculate the number of additional users that each
of your servers can support. However, this is anything but a
straightforward calculation. E-mail traffic is not smooth, but rather is
notoriously peaky. You also need to know the peak delivery rate, the
peak period during the day, the peak day of the week, and whether
monthly or quarterly peaks exist.
To obtain this
information, you need to create a Performance console that allows you to
see the entire system environment and that registers changes in the
performance of your servers. The guidelines for creating a Performance
console are as follows:
Create a Performance console that has two different sample times, for example:
Include a minimal set of counters in each console, for example:
Processor(_Total)\% Processor Time
Process(store)\% Processor Time
SMTP Server\Local Queue Length
SMTP Server\Messages Delivered/sec
MSExchangelS Mailbox\Local Delivery Rate
MSExchangelS Mailbox\Folder Opens/sec
MSExchangelS Mailbox\Message Opens/sec
Examine your busiest server to understand why it is busy and what performance problems can be resolved.
your reference log files so that you can develop historical baseline
data that allows you to see what changes have occurred and to
accommodate for additional growth over time.
By analyzing the reports
you create using your data, you can uncover patterns and predict future
trends. This trend analysis assists you to determine what steps you can
take to prevent problems on your Exchange Server 2003 servers in the
future. For example, you can predict when normal growth, such as mailbox
growth, will require you to upgrade your storage.
Protocol logs were introduced, and protocol logging configured. You can use protocol logging
to track commands that an HTTP, SMTP, or NNTP virtual server receives
from client computers and to track outgoing commands. You should
establish a schedule for reviewing protocol logs, and you should also
review the log files if your users are experiencing problems.
You can select from four types of file formats, depending on how you want to store the information. Table 1 describes these formats.
Table 1. Protocol Log File Formats
information is written to a comma-delimited ASCII text file. The data
is fixed, which means that you cannot customize the log.|
|NCSA Common Log||The
information is written to an ASCII text file that uses the National
Center for Supercomputing Applications (NCSA) format. The data is fixed,
which means that you cannot customize the log.|
information that is logged is written to a database. You must set up an
open database connectivity (ODBC)–compliant database before using this
|W3C Extended Log||The
information is written to an ASCII text file. The World Wide Web
Consortium (W3C) Extended Log file format is the most flexible format
because the data is variable, which means that you can choose what you
want to track.|
You enable protocol
logging and select the log file format for an SMTP or NNTP virtual
server by using Exchange System Manager to configure the virtual server
properties. You can also specify the schedule for creating new log files
and the location of these files (except for ODBC format). If your log
file format is W3C Extended Log File Format, you can select the items
that you want to track.
You manage HTTP
protocol logging by using the IIS Manager console to configure the Web
site properties. By default, protocol logging is enabled, and the log
file format is set to W3C Extended Log File Format.
Using a Protocol Log File
You can use a protocol
log file for general troubleshooting. Suppose, for example, users report
that they are receiving messages when their addresses do not appear on
the To or Cc lines. In this case, you can use SMTP log file data to
compare the recipients specified in a rcpt to command with addresses
posted in a message header or in the To and Cc lines of the message.
Another example is when you search the SMTP log file for the message
identity (ID) of a remote system so that you can collaborate with
another system administrator to trace a message.
can look for response codes that a receiving server returns after your
server issues an ehlo command to determine the maximum-size message that
a server will accept (for example: 250-size 60000000). You can also use
the log data to generate reports. If another server attempts to use
your server as a relay (assuming your server is properly configured to
prevent unauthorized SMTP relaying), the log file posts a numeric
response code of 550, which corresponds to Relaying Prohibited, in the
protocol status (sc-status) field. You could write a script to search
this field and tally the number of reported 550 codes.
You can use the HTTP
Monitor (HTTPMon) Resource Kit utility to monitor Web sites or
applications. HTTPMon can check Web sites and report the results to
either a log file in comma-separated values (CSV) format or in the
Windows Server 2003 server event log. You can then either use Windows
Management Instrumentation (WMI) to monitor the event log or import the
CSV output into a Microsoft Excel or SQL database for further analysis.
The utility enables
you to test that the Exchange Web site is responding to requests from
client computers in a timely fashion. It lets you test several sites
simultaneously to ensure that they are up and that they are responding
within reasonable times. You can use HTTPMon to monitor OWA servers and
identify and troubleshoot problems. You should establish a schedule for
monitoring OWA on a regular basis.
HTTPMon comprises the following three components:
Realtime Sampling Service The real-time monitoring service.
SQL Reporting Server Pulls data from monitor servers and loads it into Microsoft SQL Server.
Client Monitor A set of Web pages that displays the results from the SQL Reporting Server database.
Currently, the HTTP
Monitoring Tool is available only in the Windows 2000 Resource Kit and
is not installed by the Resource Kit Setup program. To install it,
insert the Windows 2000 Resource Kit companion CD into your CD-ROM
drive. When the Setup screen appears, click Explore The CD. In the <cdroot>\apps\httpmon directory, double-click Setup.exe and follow the directions that appear on your screen.
When you install the HTTP
Monitoring Tool, the information file (Readme.txt) and the user’s guide
(HTTPMon_whitepaper.doc) are also installed. Access these files for
information on configuring and using the tool. They are both located in
the directory where you install the tool (C:\Program Files\Httpmon in
the default installation).
You can also download the HTTP Monitoring Tool installation file from ftp://ftp.microsoft.com/bussys/utilities/httpmon.
need to manage mailbox limits on a regular basis. By default, Exchange
Server 2003 permits large mailbox sizes, and this allows users to store a
great deal of information in their mailboxes. However, this can lead to
some users having excessively large mailboxes. You can use Exchange
System Manager to manage mailbox limits and Event Viewer to check
whether mailbox sizes have reached the various limit stages that you
If you access the
mailbox node in Exchange System Manager, then you can modify the mailbox
view to include the Storage Limits column. This column provides
feedback on whether certain limits have been enforced for a specific
mailbox and, if so, what condition the mailbox is in. You can then use
Event Viewer to view the events recorded when a mailbox reaches a limit
threshold. Microsoft recommends that you monitor mailbox sizes at least
once per week. Table 2 describes the limit settings that you can specify in the Storage Limits column.
Table 2. Mailbox Limit Settings
|No Checking||Mailbox limits are not enabled for the mailbox.|
|Below Limit||The mailbox has limits set, but the mailbox usage is below these limits.|
|Issue Warning||The mailbox size has reached the Issue Warning limit and a warning message is delivered to the mailbox.|
|Prohibit Send||The mailbox size has reached the Prohibit Send limit and the mailbox-enabled user is no longer able to send messages.|
mailbox size has reached the Prohibit Send and Receive limit and the
mailbox is set to Disabled. The mailbox-enabled user cannot send
messages from this mailbox, and the mailbox is unable to receive
You can configure
diagnostic logging on an Exchange Server 2003 server to enable you to
view events in the application log in Event Viewer that indicate when
mailboxes reach the various stages of storage limit warnings. You can
also use the mailbox management process, otherwise known as Mailbox
Manager, to manage oversized mailboxes.
Mailbox Manager is
defined as a recipient policy and can be used to create reports or take
actions to clean old mail from users’ mailboxes. You can schedule the
mailbox management process to run at a specific time for regularly
scheduled cleanups, or you can run it manually. You should run the
process manually if you are in immediate need of mailbox statistics or
if you need to clear mailboxes of old mail immediately.
start the process by starting Exchange System Manager, navigating to
the relevant server, right-clicking the server, and then selecting Start
Mailbox Management Process. Mailbox management starts after a short
delay, which depends on the level of resource use on the server.
The Badmail Folder
If a message has reached
the retry limit and an NDR cannot be delivered to the sender, a copy of
the message is placed in the Badmail folder. Messages placed in this
folder cannot be delivered or returned.
Over time, messages can
accumulate in the Badmail folder. If you do not monitor the Badmail
folder regularly, your Exchange Server 2003 server can run out of disk
space. This causes the Microsoft Exchange Information Store service to
shut down. You need to establish policies for monitoring the folder and
removing messages after a certain age. Microsoft recommends reviewing
the content of the Badmail folder on a weekly basis.
Another reason for
monitoring the Badmail folder is that it could contain messages from an
external user who is attempting to relay spam e-mail through your
By default, the Badmail
folder is located in the virtual server’s home directory. You can
relocate the folder by using Exchange System Manager to access the
Messages tab in the relevant virtual server’s Properties dialog box. You
can use Windows Explorer to check the contents of the Badmail folder. A
large number of undelivered messages could indicate delivery problems
such as a DNS or network failure, or potential security problems due to
spam e-mail. You should delete messages from the Badmail folder based on
your organization’s policies. For example, you could delete messages
once per week.
The Postmaster Mailbox
account is configured to receive NDRs and is used to send the delivery
status of a message to the sender. By default, Exchange Server 2003
creates the postmaster proxy address and assigns this address to the
administrator who created the Exchange organization. It is good practice
to change this default setting so that the name of this administrator
account is not exposed to outside users.
To designate a specific user’s mailbox as the postmaster mailbox for a local SMTP domain, you add the proxy postmaster@localdomainname
to the user’s list of SMTP proxy addresses. You can associate an
existing e-mail account with the postmaster or create a dedicated
postmaster account from which the NDRs will be sent.
If you decide to create a
dedicated postmaster account, you can log on using that account by
using an Outlook profile and respond to the account messages.
Alternatively, you can delegate Send As permissions on the account to
the person to whom you have delegated the task of managing the mailbox,
and add the mailbox to that person’s Outlook profile.
establish a regular schedule for reviewing and responding to the
delivery reports contained in the postmaster mailbox. This schedule
should be based on your organization’s requirements. Some organizations
make this a daily task in an effort to reduce the number of e-mail
messages that are delivered to users who are no longer with the
organization, while others companies make this a weekly or monthly