This problem only seems to be affecting this "Sue". She can't send externally or internally using Outlook 2010. Using webmail she's fine. I've rebuilt the profile, reinstalled Outlook, repair installed Outlook and nothing works on this computer. I'll set her user account up on another computer and see if that works and post the results here.
Delivery has failed to these recipients or groups:
Bob Johnson (email@example.com)
The e-mail address you entered couldn't be found. Please check the recipient's e-mail address and try to resend the message. If the problem continues, please contact your helpdesk.
Diagnostic information for administrators:
Generating server: AGCV13K.domain.lcl
#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##
Original message headers:
Received: from AGCV10K.domain.lcl ([169.254.1.79]) by agcv13k.domain.lcl
([fe80::c893:80f1:4d72:fab9%15]) with mapi id 14.02.0247.003; Thu, 22 Mar
2012 14:40:08 -0700
Content-Type: application/ms-tnef; name="winmail.dat"
From: Sue Smith <firstname.lastname@example.org>
To: "Bob Johnson (email@example.com)"
Date: Thu, 22 Mar 2012 14:40:07 -0700