Resolving network address offline

[SimonD]

Morning all

We have a network using exchange 2000, and the users have Outlook 2000 and 97. Some of our users are mobile, and while away from the office clear their email by going on-line, and then clicking on Outlook. Our ISP then authenicates them, and passes them into outlook. They clear their emails, and log off.

The problem is arrising, when off-line, they then hit the "reply" button, and attempt to reply to an email that was sent from someone within the network.

When they go back online again, the email is returned, with the message saying:

Your message did not reach some or all of the intended recipients.

Subject: FW: Intinerary

Sent: 11/20/02 8:17 AM

The following recipient(s) could not be reached:

Alastair McLaren on 11/20/02 8:17 AM

The e-mail address could not be found. Perhaps the recipient moved to a different e-mail organization, or there was a mistake in the address. Check the address and try again.

<Doc.sleepyhead.co.nz #5.1.0>

If they simply type the users address in the "TO" field, the email is delivered. If they reply while online, it is delivered. The problem only occurs when off-line.

Can anyone offer any reasons why this is occuring, and what we could do to fix.

Thanks