Hello--I just finished migrating users from Exchange 2003 to 2007. I am getting a non-delivery on one user, on internally sent emails. This is happening for all users who try to send emails to this one user. All users are on a single internal Exchange 2007 system. The message that comes back is: "The recipient's e-mail address was not found in the recipient's e-mail system". The generated error message is: "IMCEAEX - O O=(organization name) OU=First+20administrative=20group cn=Recipents cn=(username@mydomain.local) #550 5.1.1. RESOLVER.ADR.ExRecipNotFound; not found ##" The one thing I did with this user was that after I moved his mailbox, I had to delete and recreate his account on the server to fix some Outlook issues. I have done some research on this, which mostly says to delete the .nk2 file on individual workstations. However this has NOT fixed the issue. Can anyone advise on what other steps I might take? Thank you!

When you say 'The one thing I did with this user was that after I moved his mailbox, I had to delete and recreate his account on the server to fix some Outlook issues.' what exactly did you delete? Did you delete his AD object or mailbox? Looks like a LegacyDN issue, are users in Cached Mode when they try and send e-mail to this user?

Thank you for the reply! I clicked on his name in Server/management/users and chose Delete. There was also a prompt if I wanted to delete the mailbox, which I chose. They are using Outlook 2007 in cached mode.

When you say 'The one thing I did with this user was that after I moved his mailbox, I had to delete and recreate his account on the server to fix some Outlook issues.' what exactly did you delete? Did you delete his AD object or mailbox? Looks like a LegacyDN issue, are users in Cached Mode when they try and send e-mail to this user?

So what's happening is that your users are attempting to send mail to this person via a cached address in Outlook which contains their LegacyDN of the account you deleted. As the account no longer exists, even if you recreate it because the LegacyDN will be different, it's bouncing. Any chance that the original mailbox and/or AD object can be recovered or you happened to take an LDAP export of the LegacyDN names for all the mailboxes before you started the migration? If not, users will either need to chose this particular mailbox out of the GAL or rebuild their Outlook cache (which is more painful to users IMO) Thanks, Jeff

So what's happening is that your users are attempting to send mail to this person via a cached address in Outlook which contains their LegacyDN of the account you deleted. As the account no longer exists, even if you recreate it because the LegacyDN will be different, it's bouncing. Any chance that the original mailbox and/or AD object can be recovered or you happened to take an LDAP export of the LegacyDN names for all the mailboxes before you started the migration? If not, users will either need to chose this particular mailbox out of the GAL or rebuild their Outlook cache (which is more painful to users IMO) Thanks, Jeff

Hi zooeyhall, The issue is caused by the outlook cache the account's legacyexchangedn in the NK2 file of all other client ends. So, you could let the users delete the special cache through outlook, or the whole NK2 file. Or you could add it back as a custom x500 address in their SMTP tab. Regards! Gavin TechNet Subscriber Supportin forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi zooeyhall, The issue is caused by the outlook cache the account's legacyexchangedn in the NK2 file of all other client ends. So, you could let the users delete the special cache through outlook, or the whole NK2 file. Or you could add it back as a custom x500 address in their SMTP tab. Regards! Gavin Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

It appears that if users specifically select the problem address from the GAL, then it sends ok. Since it only seems to be affecting the address of this one user, I think we can work around it. Thanks for the reply!