Here's a Microsoft support document for reasoning and solution behind this 'feature' of Outlook 2002.
OL2002: Add-in or Custom Solution Causes a Warning to Appear
The information in this article applies to:
Microsoft Outlook 2002
SUMMARY If you use a third-party add-in, custom solution, or other program that integrates with Outlook 2002, you may receive one or more of the following warnings:
A program is trying to automatically send e-mail on your behalf. Do you want to allow this? If this is unexpected, it may be a virus and you should choose "No". A program is trying to access e-mail addresses you have stored in Outlook. Do you want to allow this? If this is unexpected, it may be a virus and you should choose "No". These warning messages are commonly associated with software that is designed to synchronize Outlook data with handheld computers, but may occur with any type of add-in or custom solution.
MORE INFORMATION Outlook 2002 includes security features to prevent other programs from accessing your e-mail addresses or sending e-mail messages on your behalf.
A few trustworthy programs may access contacts or e-mail messages to retrieve e-mail addresses for various reasons, but unsuspecting users have been affected by some viruses that do the same in order to propagate. In order to spread through e-mail messages, these viruses send e-mail messages that contain their malicious code to other users. Usually, this occurs without a user being aware of it.
The security features built into Outlook 2002 make discernible these processes that are usually transparent to the user.
Once you have verified that the program or add-in accessing e-mail addresses or sending e-mail messages on your behalf is trustworthy, you can choose to allow it to access the e-mail addresses or send the e-mail messages.
One example of a program that accesses Outlook e-mail addresses is the Component Object Model (COM) add-in installed by ICQ 2000. For more information, please see the following article in the Microsoft Knowledge Base:
Q288083 OL2002: ICQ Integration Causes Address Security Warning How to Customize the Security Settings In a Microsoft Exchange Server environment, an administrator may want to control Outlook's security behavior. For more information, please see the following Microsoft Knowledge Base articles:
Q290499 OL2002: Administrator Information About E-mail Security Features Q290497 OL2002: Cannot Access Attachments