Exchange FAQs
How can I modify the Exchange Server 2003 Outlook Web Access (OWA) timeout that's
applied when OWA has forms-based authentication enabled?
By default, when OWA has forms-based authentication enabled, sessions have a
15-minute inactivity timeout for public or shared computers and 24 hours for
a private computer. If you're using a public computer to compose a long email
message that takes more than 15 minutes to write, the session will time out
and you won't be able to send the message. You can change this timeout value
(which is the cookie lifetime) by using this procedure:
- Log on to the Exchange server as an Administrator.
- Start the registry editor (regedit.exe).
- Navigate to the HKEY_LOCAL _MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWEB\OWA
subkey.
- From the Edit menu, select New, DWORD value.
- Enter a name of "PublicClient Timeout" and press Enter.
- Double-click the new entry and set it to the desired number of minutes before
a timeout (1 to 4320), set the type to decimal, and click OK.
- To set the timeout period for a private client, repeat the process of creating
a DWORD value, but this time enter a name of "TrustedClient Timeout" and again
set the value to the number of minutes before a timeout. (The value for private
computers should be significantly higher than for public computers.)
- Stop and restart the World Wide Web (WWW) Publishing service by using these
commands at the command line:
net stop w3svc net start w3svc
John Savill
What does the Microsoft Antigen product family do?
The first round of Microsoft-branded Sybari products—Microsoft Forefront
Security for Exchange Server, Antigen for SMTP Gateways, Antigen Spam Manager,
and Antigen Enterprise Manager—are ready to hit the market. Eventually,
all these products will be included in the Microsoft Forefront line of security
products, but the current versions offer a compelling solution for Microsoft
Exchange Server email infrastructures. Here's what you need to know about the
Antigen family of products.
Spam protection at the server level. The Antigen products are designed
to protect Exchange email servers, although Antigen for SMTP Gateways also supports
the SMTP server function in Windows servers. (Microsoft is also working on Antigen
products for Windows SharePoint Services and IM.) An Antigen for Exchange product
has existed for roughly 10 years, and it has always focused solely on managed
enterprise servers, not consumer or desktop products. Customers have always
applauded Antigen because it only minimally affects performance and easily integrates
with Microsoft's management technologies.
Unlike some antivirus solutions, Antigen doesn't rely on just one antivirus engine. Instead, administrators can install and enable multiple antivirus engines, as the situation demands, to obtain the best antivirus protection possible. Sybari never saw itself as an antivirus engine lab, so it partnered with several antivirus engine companies, and Microsoft continues to benefit from these established relationships. Antigen also includes a new antivirus engine designed by Microsoft that's based on its experience protecting millions of MSN and Hotmail accounts.
The Antigen email-protection products come with five antivirus scanning engines:
Microsoft, Sophos, CA Vet, CA InoculateIT, and Norman. If you buy the Antigen
Messaging Security Suite, which includes Forefront Security for Exchange Server,
Antigen for SMTP Gateways, and Antigen Spam Manager, you also get Kaspersky,
AhnLab, Authentium, and VirusBuster engines. You can use any combination of
engines to get the best protection, but Microsoft recommends activating no more
than five antivirus scanning engines per installation.
Why would you need multiple engines? When a virus appears, companies that make antivirus scanning engines race to be the first to market with new signatures. By using multiple engines, you're more likely to quickly receive signatures for all new viruses than you are if you rely on just one vendor.
What's new in Antigen. Antigen underwent Microsoft's grueling Security
Development Lifecycle code review to ensure that it uses the lowest possible
security privileges and ships with the most secure out-of-the-box configuration.
These precautions are important because hackers often use antivirus products
as an attack vector. Antigen also provides greatly enhanced support for Exchange
clusters.
Recommendations. If you're already a Sybari customer, there probably
aren't enough improvements in Antigen to warrant an upgrade. But if you're still
looking for an antivirus solution that offers superior protection and deep integration
with Active Directory (AD) and other Microsoft management tools, consider Antigen.
Future versions will benefit from integration with other Forefront solutions
and Exchange Server 2007's roles-based infrastructure.
Paul Thurrott
SharePoint FAQs
How can I use Microsoft Front-Page to back up or restore a Windows SharePoint
Services site?
FrontPage lets you create archives of SharePoint sites for backup and restore
purposes. To do so, perform the following steps:
- Use Microsoft Internet Explorer (IE) to open the SharePoint site.
- From the File menu, select Edit with Microsoft Office FrontPage.
- In FrontPage, select Tools, Server, Backup.
- Check the Include subsites in archive option and click OK.
- Select a folder and filename for the Web-site archive file (.fwp) and click
Save.
- After the backup is done, click OK in the Backup completed dialog box.
To restore a site, perform the following steps:
- Create a new site (to which the archive will be restored). When the wizard
asks you to select a template, close IE so that no template is applied.
- In FrontPage, open the site that you just created (Click File, Open Site,
and enter the URL of the site you just created).
- In FrontPage, select Server, Restore Web Site, from the Tools menu.
- Select the name of the archive file and click Open.
- Click OK to restore the Web site.
John Savill
How can I make links in Microsoft SharePoint technologies
open in a new browser window?
By default, SharePoint links open in the existing browser window. You can find
several solutions for this behavior on the Web (some listed at the end of this
FAQ), but I found the following solution to be the easiest:
- Use Microsoft Internet Explorer (IE) to open the SharePoint page containing
the links.
- From the File menu, select Edit with Microsoft Office FrontPage.
- In Microsoft FrontPage, rightclick the section with the links, and from
the displayed context menu select Convert to XSLT Data View.
- Right-click one of the links and select Hyperlink Properties.
- From the displayed dialog box, click the Target Frame button.
- Select New Windows and click OK for all dialog boxes.
- Save the page changes.
Now, when someone clicks a link, the page will open in a new window. You can
find other solutions for this behavior at http://mindsharpblogs.com/todd/archive/2005/08/16/654.aspx
and http://andrewconnell.com/blog/articles/SharepointLinksListOpenIn
NewWindow.aspx.
John Savill
What's Sunbelt Messaging Ninja?
Sunbelt Software's Sunbelt Messaging Ninja offers spam, virus, and attachment
filtering for Microsoft Exchange 2000 Server and later. Ninja's policy-based
approach lets you create different rules for users and groups and enforce policies
according to destination, source, and direction (e.g., incoming, outgoing).
You can set antispam policies to allow or block senders according to attributes
in any message field. Ninja can even flag messages according to the character
set used (e.g., quarantining messages that use the Russian Cyrillic alphabet).
Ninja uses Authentium and BitDefender antivirus engines and Cloudmark's signature-based
spam filter as well as Sunbelt's own heuristic engine. Ninja also supports Realtime
Blackhole Lists and Sender Policy Framework. The product runs on your Exchange
servers and has the unique ability to scan internal email. The trade-off, however,
is that Ninja uses processor resources and can increase the server load by up
to 20 percent.
Installation is a 20-minute process that requires restarting the Exchange service.
After installation, I quickly created policies and administered them without
resorting to the documentation. You control Ninja through Microsoft Management
Console (MMC). Managing multiple servers requires opening multiple MMC instances,
which might be a hassle for multiple-site organizations. A replication feature
maintains consistency among clusters or multiple servers.
Comparable solutions offer similar functionality at a lower price. Because
they typically run on the gateway, however, such products can't filter internal
email or provide Ninja's granular configuration options. Ninja's flexibility
makes it a useful application for organizations that don't require management
from a remote installation.
Joel B. Barker
What approach should I take in developing an email-security
strategy?
Because of the danger of viruses, Trojan horses, and spyware and because email
is now the main attack vector, most organizations rely on multiple layers of
defense. Those layers can include a packet-filtering firewall, an email firewall,
and a demilitarized zone (DMZ) mail server.
The first layer of defense—and the layer that best protects the underlying
network and provides a crucial level of protection for network-oriented applications—is
the packet-filtering firewall. A packet-filtering firewall understands networks
at the TCP/IP layer, including such matters as TCP, UDP, and ports. This type
of firewall is configured to let only certain types of incoming packets through
to specifically allowed ports on the internal hosts that the firewall protects.
For example, a firewall might allow incoming packets on TCP port 25 on the DMZ
mail server and TCP port 80 or TCP port 443 on the DMZ Web mail server.
The second layer of defense is an email firewall, one example of an application-level
firewall. This type of firewall works at a higher level in the protocol stack.
It not only understands SMTP but can scan the content of mail envelopes and
mail content to detect spam, phishing attacks, and viruses. The email firewall
is usually hardened against SMTP-based attacks (e.g., buffer-overflow attacks),
so the DMZ mail server is less susceptible to such attacks. An email firewall
protects email systems (i.e., computer systems that provide mail service) as
well as providing a layer of protection for internal users from dangerous email
messages in their mailboxes.
Note that email firewalls must provide comprehensive antivirus capabilities
to properly defend against both known and unknown viruses. Much antivirus software
has been reactive. However, because of how quickly viruses now spread and because
many viruses are polymorphic, a reactive approach is no longer enough. Antivirus
software must also provide predictive scanning, meaning that it should be able
to perform heuristic scanning to detect key characteristics that identify a
virus rather than needing to know an exact signature. Reactive scanning still
has a place in virus defense, but real-time defense against zero-day threats
requires predictive scanning from antivirus software.
The third layer of defense is a well-configured DMZ mail server. This server
accepts only mail destined for the domains that it owns—that is, for internal
users. This approach prevents spammers from using this mail server for relaying
spam. The DMZ mail server is also hardened so that attacks that jump to it from
the email firewall (e.g., invalid input that the email firewall accepts and
passes on to the DMZ mail server) don't compromise it.
Finally, additional layers of defense can be beneficial, such as an intrusion
detection system and a separate DMZ Web mail server. (Because Web mail servers
usually run complex Web applications, they often provide an avenue for an attack
that can compromise internal systems.)
Dustin Puryear
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MORE ONLINE
Follow these links to access the resources mentioned in this month's Exchange
Ideas.
Exchange FAQs John Savill's FAQ for Windows, http://www.windowsitpro.com/windowsnt20002003faq
Microsoft's Antigen products "What You Need to Know About Microsoft Antigen,"
InstantDoc ID 92861
SharePoint FAQs John Savill's FAQ for Windows, http://www.windowsitpro.com/windowsnt20002003faq
Product Review: Sunbelt Messaging Ninja "Sunbelt Messaging Ninja," InstantDoc
ID 93582
Developing an email-security strategy Excerpted from Spam Fighting and
Email Security for the 21st Century (Windows IT Pro eBooks). Download
this eBook for free at http://www.windowsitpro.com/ebooks.
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