This is on a Server 2003 R2(SP2) with Exchange 2003 SP2 Recently we have had a few people who are getting "System Admin Undeliverable" messagesas indicated below. I can undestand somethings to external users, but users on the same mail server in the same domain?This is only happening on two users that I can think if and there have been recent changes for them both. One changed computers and we migrated his profile from his old computer and the other had her name, user name and email address change.The other thing is it's random. User one could send an email 5 times to the same person and then the 6th bounces.From: System Administrator Sent: Friday, November 23, 2007 9:48 AMTo: Stan Subject: Undeliverable: Santa Cruz internet accessYour message did not reach some or all of the intended recipients.Subject: Santa Cruz internet accessSent: 11/23/2007 9:48 AMThe following recipient(s) could not be reached:'Mike ' on 11/23/2007 9:48 AMThe message could not be delivered because the recipient's destination email system is unknown or invalid. Please check the address and try again, or contact your system administrator to verify connectivity to the email system of the recipient.Thanks!

I'm getting the same message, just started last week for 1 of our users... it's random as well... the odd thingis that the error appears even when the user tries to email himself (as a member ofa distribution group). The other users in the same distro group get the messages as they are all inter-office as well. Same setup, Windows Server 2003 w/ SP2,Exchange Server 2003 w/ SP2. Client using Outlook 2003 on XP Professional w/ SP2.

Hi, I do started receving System administrator undeliverable email messages. If you find any solution for this problem please help to solve it. My email address is mdshafi@canada.com Thanks.

I forgot to mark this as resolved. What we found was there were two problems. The first was user error and the second was that he was trying to send emails to bad names in his cached names from Outlook. So what you have to do is start to type the persons name that you are trying to send email to. When the name comes up, you highliht it and then hit the delete button on your keyboard. What this does is delete it from your name cache. You can also get rid of the cachecompletly by following the following instructions: Use the steps in the following section to reset the Outlook nickname cache for Microsoft Windows XP. 1. Quit Outlook. 2. Click Start, and then click Search. 3. In the Search Companion left-side panel, click All files or folders. 4. In the All or part of the file name: box, type *.NK2. 5. In the Look In box, click to select your local hard disk. 6. Click More advanced options, click to select Search hidden files and folders check box. 7. Click Search. 8. Right-click the .NK2 file with the name of the profile that you want to reset, and then click Rename. 9. Rename the file to profilename.bak, and then press ENTER. 10. Quit Windows Explorer. 11. Restart Outlook.Outlook will generate a new nickname cache. You can also just delete the file... www.isworks.com