outlook 2007 delayed email not working

Can you provide any more details?  Is he leaving Outlook open during the time frame of the delayed delivery? Does  the message leave his Outbox?  Can you trace it in the SMTP logs of the server to see if any attempt is made to deliver the email?  Are the emails that fail addressed to an internal or external recipient? Is there any specific time of day or date range, or specific recipients, that seem to be common among the failed emails? How does he know it fails - does he get any type of NDR or other error report?

we found that you had to leave the client open with the delayed mail (cached laptop user) -- if you closed the client, the delayed message would not send.  I assume this is not the case when caching is off.

we need to know you Outlook & Exchange versions too.

We are using 2007 for both server and client.  The emails that fail are after normal business hours so it would be when his client is closed. I will have him leave the client open to see if that is the reason.

in our case that was the issue, we just advised management staff of this so they knew the steps to take if delayed emails had to be sent.