No. They're perfectly free to delete and ignore any requests.

Signature
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003
http://www.turtleflock.com/olconfig/index.htm
and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx
> Is there a way to require that attendeees email me their responses to a
> meeting request?
>
> Thanks!