I've got a user with Outlook 2003 SP3 that is experiencing the error described below. This issue only occurs when the user emails this particular email address. I've tried switching outgoing mail servers from the ISP's outgoing mail server to the email hosting service's outgoing mail server and the user still has this problem. I also recently changed the email hosting to another service and now and using their outgoing mail server and the problem is still happening. The user is able to email that address from the GoDaddy webmail interface.
My guess is that it doesn't appear to be a Outgoing mail server issue. Also of interest, when I send the email it immediately pops into the Inbox as undeliverable. It's so fast that it doesn't feel like it has had time even to leave the computer.
I've seen issues online where Outlook causes that problem, but they all appear to be related to Outlook 2003 SP1. I've done all the updates on this computer, so I don't think that's an issue.
Outlook is configured with Exchange to store the email data, although the email is not hosted with Exchange. They have a GoDaddy POP account configured to check their email.
Your message did not reach some or all of the intended recipients.
Sent: 7/21/2009 9:23 AM
The following recipient(s) could not be reached:
Diane & Stewart (email@example.com) on 7/21/2009 9:23 AM
None of your e-mail accounts could send to this recipient.