Why is a new attendee created when the original attendee accepts a meeting invitation?

Issue encountered

In Outlook, create a meeting and invite an attendee. The attendee will receive this invitation and receive the option to accept or decline and send the response back. Under certain circumstances, when the response is received it will create a new attendee in the event instead of updating the original attendee.

Outlook (not KOC) matches an attendee by her whole name e.g. "John Smith <john.smith@domain.com>" not only by <john.smith@domain.com>. That means if you invite John and he has set his whole name as "Johny <john.smith@domain.com>" and answers you, then you will encounter this problem because "John Smith <john.smith@domain.com>" is not the same text as "Johny <john.smith@domain.com>".


This behavior is a problem of Outlook. It occurs for all supported versions of Microsoft Outlook - 2000, XP and 2003.

Because Microsoft has not fixed this problem we only have a workaround for this issue.

To prevent this issue, only use the addresses from the Public Contacts address book when sending an invitation. Do not enter the mail address manually. You will also wish to disallow your users from overriding their email addresses and names in KOC's dialogue.