The Microsoft Office 2003 Service Pack 1 (SP1) includes many improvements and additions to the Microsoft Office Outlook 2003 Junk E-mail Filter features. The "More Information" section provides additional details about the improvements and the additions to the Outlook 2003 Junk E-mail Filter features.

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How to stop client rules from running on junk e-mail messages

Before providing you with information about the improvements to the Junk E-Mail Filter, it is important to quickly summarize when and how the Junk E-mail Filter works in Microsoft Exchange and in Microsoft Outlook.

If you are using Outlook 2003 in Online mode, the Microsoft Exchange 2003 server filters your e-mail messages based on the domain and on the e-mail address of the sender. In this situation, the Blocked Senders List, the Safe Senders List, and the Safe Recipients List are used. However, one limitation of using the Exchange 2003 server is that the e-mail message is not filtered based on the Subject box or on the text that is in the body of the e-mail message. This is a limitation of the Junk E-mail Filter when you use Outlook 2003 in Online mode with Exchange 2003 server. Note, this limitation also occurs for OWA 2003.

If you are using Outlook 2003 in Online mode with a mailbox that is on either a Microsoft Exchange 2000 server or on a Microsoft Exchange 5.5 server, junk e-mail filtering is not performed by Microsoft Outlook or by Microsoft Exchange. Outlook lets you to create the Blocked Senders List, the Safe Senders List, and the Safe Recipients List, but these lists are not used to filter junk e-mail messages in this configuration. Note that Outlook displays a warning message advising you that the Junk E-mail Filter features are not available in this configuration.

If you are using Outlook 2003 in Cached Mode, or if you are using a local personal folders (.pst) file store (for example, if you are using a POP3 account), the client-side Junk E-mail Filter scans all the sections of an e-mail message for junk e-mail. Additionally, if you are using either an Exchange Server 2003 account or a local .pst store with a non-Exchange account, you can use the Blocked Senders List, the Safe Senders List, and the Safe Recipients List to filter junk e-mail.

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How the Junk E-mail Filter functions in Outlook 2003 without Office 2003 SP1 installed

The following information describes the how the Junk E-mail Filter functions before you install Office 2003 SP1:

•	Client-side rules run even if the e-mail message is determined to be junk e-mail in the Outlook 2003 if you are using Outlook 2003 in a Cached Mode profile, or if you are using a non-Exchange account.
•	If the Exchange 2003 server determines that an e-mail message is junk e-mail, the server-side rules do not work because the junk e-mail rule on the server has an implicit "stop processing more rules" action.
•	If the Exchange 2003 server determines that an e-mail message is considered to be junk e-mail, client-side rules are also prevented from working.
•	Server-side rules do not run on the server if Outlook determines that an e-mail message is junk e-mail

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How the Junk E-mail Filter functions in Outlook 2003 after you install Office 2003 SP1

If you have Office 2003 SP1 installed on your computer, e-mail messages are scanned to see if it is junk e-mail before Outlook 2003 runs any client-side rules. If the e-mail message is determined to be junk e-mail, the rule will not be processed for that e-mail message. If the e-mail message is determined not to be junk e-mail, the rule processing continues as expected.

The following table outlines the scenarios that are covered by rules and by the Junk E-mail Filter.

E-mail message is determined to be junk e-mail by:	Rule	Mode	Pre-SP1	SP1
Exchange Server 2003	server-side	Online or Cached	Rule does not run.	Rule does not run.
Exchange Server 2003	client-side	Online or Cached	Rule does not run.	Rule does not run
Client	server-side	Cached	Rule runs	Rule runs.
Client	client-side	Cached (or non-Exchange account)	Rule runs.	Rule does not run.

If you try to use the Run Rules Now option on the Rules and Alerts tab on the Junk E-mail folder, the selected rules will run on all e-mail messages that are contained in the selected folders and optionally, their sub folders. This is consistent with providing the ability to use the Run Rules Now on the Deleted Items folder.

You can automatically add recipients to the Safe Senders List

If you have Office 2003 SP1 installed on your computer, the Outlook 2003 Junk E-mail Filter has been improved to better define what is consider junk e-mail by treating e-mail threads that are initiated by you as safe e-mail messages. Because you sent the original e-mail message, any replies that come back to you are ignored by the Junk E-mail Filter, regardless of their content or their domain.

Outlook 2003 will view the current Safe Senders List and then add each valid SMTP recipient's e-mail address that is in the e-mail message to the Safe Senders List, if it has not already been added.

Note, internal Exchange e-mail addresses are ignored and are not added to the Safe Senders List.

Configuration and deployment to configure the Safe Senders List

By default, this Junk E-mail Filter is not turned on in Outlook 2003. However, you can configure the Safe Senders tab in Junk E-mail Options. To do this, follow these steps:

1.	In Outlook, click Tools, click Options, and then click Junk E-mail on the Preferences tab.
2.	Click the Safe Senders tab, click to select the Automatically add people I e-mail to the Safe Senders List check box, and then click OK two times.

This configuration can also be deployed with a System Policy. Use the following registry data value to configure the Safe Senders List:

Registry key:HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\11.0\Outlook\Options\Mail
Value: JunkMailTrustOutgoingRecipients
Type: DWORD
Data: 0=disabled; 1=enabled

Conflict handling

If a sender exists in both the Safe Senders List and the Blocked Senders List, the information that is in the Safe Senders List is used. The e-mail messages that are sent from an e-mail address in either of these two lists will never be considered junk e-mail. The resolution to any conflicts caused by this configuration is to manually remove the sender’s e-mail address from either the Safe Senders List or the Blocked Senders List.

If a specific SMTP e-mail address is listed in the Blocked Senders List, but the SMTP domain for that user is included in the Safe Senders List, the e-mail message is treated as junk e-mail. By design, the Junk E-mail Filter uses the specific SMTP e-mail addresses if there is a conflict between the Safe Senders List and the Blocked Senders List with any entry that contains only the SMTP domain name.

Blocking International e-mail

Office 2003 SP1 incorporates two new lists in the Junk E-mail Filter that are designed to block additional types of e-mail messages based on encoding text and the country code:

•	The Blocked Encodings List
•	The Blocked Top-Level Domains List

These two new lists allow you to filter e-mail messages that contain text that appears to be in another language. Additionally, the two new lists filter e-mail messages if the sender’s domain ends with a two-character country code in their SMTP address. These new lists allow you to more granularly control the e-mail messages that are considered as junk e-mail messages when they are not caught by the Junk E-mail Filter. Both lists can be accessed on the new International tab in the Junk E-mail Options dialog box.

With these two new lists enabled, the e-mail message is moved to the Junk E-mail folder when you receive an e-mail message that either matches a blocked encoding or a blocked top-level domain. The following list outlines how e-mail message are handled when you use the Junk E-mail Filter with the Blocked Encodings List and the Blocked Top-Level Domains List:

1.	You receive an e-mail message.
2.	Outlook 2003 determines whether the sender's address or domain is in the Safe Senders list. The complete SMTP address is checked against the Safe Senders List before the domain name is checked against the list. If the sender's address or domain is in the Safe Senders list, Outlook 2003 does not consider this e-mail message as junk e-mail, and it stops analyzing the e-mail message. If the sender's address or domain is not in the Safe Senders list, Outlook 2003 continues analyzing the e-mail message. Note If there is at least one sender in the Safe Recipients list. Outlook 2003 does not consider this e-mail message as junk e-mail, and it stops analyzing the e-mail message.
3.	Outlook 2003 determines whether the sender's address or domain is in the Blocked Senders List. If the sender's address or domain is not in the Blocked Senders List, Outlook 2003 does not consider this e-mail message as junk e-mail, and it continues analyzing the e-mail message. If the sender's address or domain is in the Blocked Senders List, Outlook 2003 moves the e-mail message to the Junk E-mail folder.
4.	Outlook 2003 determines whether the e-mail message encoding is in the Blocked Encodings List. If the e-mail message encoding is not in the Blocked Encodings List, Outlook 2003 does not consider this e-mail message as junk e-mail, and it continues analyzing the e-mail message. If the e-mail message encoding is in the Blocked Encodings List, Outlook 2003 moves the e-mail message to the Junk E-mail folder.
5.	Outlook 2003 determines whether the sender's country is in the Blocked Top-Level Domains List. If the sender's country is not in the Blocked Top-Level Domains List, Outlook 2003 does not consider this e-mail message as junk e-mail, and it continues analyzing the e-mail message. If the sender's country is in the Blocked Top-Level Domains List, Outlook 2003 moves the e-mail message to the Junk E-mail folder.
6.	The Outlook 2003 Junk E-mail Filter analyzes the e-mail message body and the Subject box. If there are no restrictions based on your Junk E-mail Filter settings, the e-mail message is not considered junk e-mail, and the e-mail message is moved to the Inbox folder. If the e-mail message matches the criteria that you have set for the Junk E-mail Filter settings, the e-mail message is moved to Junk E-mail folder.

How to configure either blocked encodings or blocked top-level domains

To configure either blocked encodings or blocked top-level domains, click either the Blocked Encodings option or the Blocked Top-Level Domains option on the International tab in the Junk E-mail Options dialog box. The following behaviors apply to both the Blocked Encodings option and the Blocked Top-Level Domains option:

•	By default, there are no encodings or top-level domains blocked.
•	To select all items in either the Blocked Encodings or the Blocked Top-Level Domains tabs, and then click Select All. This is helpful if you want to enable more items than you disable.
•	To quickly disable all check boxes on either the Blocked Encodings or the Blocked Top-Level Domains tabs, click Clear All. This is helpful in the situation where you want to reset the dialog box back to the default settings.

Just like the Safe Senders List, the Blocked Senders List, and the Safe Recipients List that are available before Office 2003 SP1, the Blocked Encodings List and the Blocked Top-Level Domains List are stored in your mailbox and in your Outlook profile in the registry. However, you cannot deploy the new list settings to multiple computers or mailboxes. You must manually configure the settings on each computer.

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Limit of the junk e-mail lists

By default, you have the following limit on the total size of the junk e-mail lists:

•	Exchange: 512 kb (cumulative for all lists combined)
•	POP3/IMAP: none

Therefore, if you are using these lists extensively with an Exchange 2003 mailbox, you might hit the 512 KB limit. The workaround for this is to increase the limit by using the following registry key on the Exchange 2003 server:

Registry key: HKLM\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem
Value: Max Extended Rule Size
Type: DWORD
Data: maximum size, in bytes, you want to allow for the junk e-mail rule

Note, the junk e-mail list limit is not new to Office 2003 SP1. It is only mentioned in this article because you may experience the limit a bit faster with the additional block lists that are available in Office 2003 SP1.

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