When sendingmeeting updates or cancellations using OL2007 Client on an Exchange 2000 Server to the recipients Exchange 2007 mailbox the updates are returned with a DSN 4.4.7 error. This happens with calendar updates only--email messaages are delivered in a timely manner.http://support.microsoft.com/kb/938650references Exchange 2003 to 2007--is it relavent for Exchange 2000? Could not deliver the message in the time limit specified. Please retry or contact your administrator. <mailserver.domain.org #4.4.7>

The KB is applied to exchange 2003, not exchange 2000 Please raise the diagnostics logging and protocol logging, and reproduce the issue. Then, check the application log and SMTP log General troubleshooting for transport issues in Exchange 2000 Server and in Exchange Server 2003

there is no fix for exchange 2000 per Microsoft. we upgraded to ex2003 and then transitioned to 2010.