XCON: 404 Error When an IMAP4 User Tries to Open a Meeting Request Link (330298)

SYMPTOMS

When an Internet Message Access Protocol, Version 4rev1 (IMAP4) user tries to open meeting requests received through IMAP4 clients, the user may receive 404 error messages.

The URL that IMAP4 constructs for meeting requests uses the following format:
http://domain.com/exchange/FirstName.LastName/Inbox/Meeting.EML

If you replace FirstName.LastName in this URL with the mailbox alias, the user can successfully reach the meeting request.

CAUSE

This problem is caused by two conditions:

A recipient policy sets primary Simple Mail Transfer Protocol (SMTP) proxy addresses to a form that does not match the http virtual root (v-root) for Exchange 2000. Therefore, if a customer has configured their http v-root for Exchange 2000 as "example.domain.com", the following recipient policy would create SMTP proxy addresses that do not match the v-root:
FirstName.LastName@example.com (%g.%s@example.com)
For additional information about recipient policies, click the following article number to view the article in the Microsoft Knowledge Base:
285136 XADM: How to Customize the SMTP E-mail Address Generators
Additional proxy addresses exist that match the Exchange 2000 v-root ("example.domain.com") for the right side of the address, but do not match the left side (for example, if it is set to be the mailbox alias).

The following scenario illustrates how this situation can occur.

The http v-root for Exchange 2000 points to "example.domain.com" . A user's primary SMTP proxy address is "%g.%s@domain.com". The problem occurs because the user has two different SMTP addresses: FirstName.LastName@domain.com (the primary) and FLastName@example.domain.com. Exchange 2000 tries to use the left side of the user's primary SMTP address (FirstName.LastName) to find their calendar , but the http v-root that is used (/Exchange) is set to example.domain.com. The 404 error occurs when Exchange 2000 tries to find the calendar for the nonexistent SMTP address FirstName.LastName@example.domain.com.

RESOLUTION

To resolve this problem, always make sure that the Recipient Update Service sets a primary default address that matches an Exchange 2000 virtual root. Additionally:

You can change the default Recipient Update Service policy to "@example.domain.com".
You can change the Exchange 2000 virtual root to "example.com"
You can create a new Exchange 2000 virtual root for "example.com" and configure IMAP4 users to use the new v-root.