In exchange management console (2007) I deleted a distribution list called 'IT'. My end game was to make 'IT' a user mailbox so it could be added to my department user's outlook as separate mailboxes. But after deleting it in AD and recreating it in both AD and Exchange I am getting an undeliverable message when attempting to send to it.

How long did you wait? It can take a while for the clients to pick up on the change, particularly if you use offline address books. You may also need to clean the existing cached entry from Outlook. If you do use OABs, you can try to update the server's view of the world manually, and then Outlook's via a manual address book sync. Updating the server: Open an elevated Exchange Powershell prompt Run Get-GlobalAddressList | Update-GlobalAddressList Run Get-OfflineAddressBook | Update-OfflineAddressBook Either wait a few minutes or check for MSExchangeSA Event ID 9107 in the application event log, as this gives Update-OfflineAddressBook a chance to complete Run Update-FileDistributionService -Identity ExchangeSrv01 Updating Outlook (2010; 2007 can be found under the Actions menu, from memory): Select the Send/Receive tab Send/Receive drop-down list -> Download Address Book Accept the defaults and let the process finish Don't bother trying the following step unless you've done the above, or you may well end up re-caching the wrong entry if your address book isn't up to date. Removing the cached address entry from Outlook: Compose a new e-mail (you're not actually going to send it) Start typing the address in the To field (or CC, etc) When you see it appear in the drop-down list of suggestions, use the Up and Down arrows on your keyborad to highlight the address then use the Delete key to remove the entry Type the address back into the To field and this time resolve it and try sending a test e-mail. It hopefully gets through now. Cheers, Lain

How long did you wait? It can take a while for the clients to pick up on the change, particularly if you use offline address books. You may also need to clean the existing cached entry from Outlook. If you do use OABs, you can try to update the server's view of the world manually, and then Outlook's via a manual address book sync. Updating the server: Open an elevated Exchange Powershell prompt Run Get-GlobalAddressList | Update-GlobalAddressList Run Get-OfflineAddressBook | Update-OfflineAddressBook Either wait a few minutes or check for MSExchangeSA Event ID 9107 in the application event log, as this gives Update-OfflineAddressBook a chance to complete Run Update-FileDistributionService -Identity ExchangeSrv01 Updating Outlook (2010; 2007 can be found under the Actions menu, from memory): Select the Send/Receive tab Send/Receive drop-down list -> Download Address Book Accept the defaults and let the process finish Don't bother trying the following step unless you've done the above, or you may well end up re-caching the wrong entry if your address book isn't up to date. Removing the cached address entry from Outlook: Compose a new e-mail (you're not actually going to send it) Start typing the address in the To field (or CC, etc) When you see it appear in the drop-down list of suggestions, use the Up and Down arrows on your keyborad to highlight the address then use the Delete key to remove the entry Type the address back into the To field and this time resolve it and try sending a test e-mail. It hopefully gets through now. Cheers, Lain

I figured this out. You also arrived at the right conclusion (much faster than me I must add). The cached entry in outlook was causing the entry to fail. I was thrown off because I tried to just manually type it in, and that didn't work so I ruled it out. It wasn't until later when I tried to run outlook not in cached mode and deleted the entry in the .N2K file that it worked. I am still not sure why Exchange had so much trouble both the list and the new email both go to it@ourdomain.com Thank you so much for your quick response and correct answer. Thanks, Kyle

I read your full answer after posting my solution; man I'm on a roll today. My solution would be hard to roll out to all users. I tried updating the Global Address List. This is the error I receive: WARNING: The recipient "OurDomain.com/Microsoft Exchange System Objects/Offline Address Book - First Administrative Group" is invalid and could not be updated. WARNING: The recipient "OurDomain.com/Microsoft Exchange System Objects/Schedule+ Free Busy Information - First Administrative Group" i invalid and could not be updated. WARNING: The recipient "OurDomain.com/Microsoft Exchange System Objects/Employees" is invalid and could not be updated. WARNING: The recipient "OurDomain.com/Microsoft Exchange System Objects/Master Calendar 85971073" is invalid and could not be updated. [PS] C:\Documents and Settings\administrator.MCKEE> I am looking this up now, but thought I would update you if you had any thoughts. Thanks, Kyle

It Totally Depands on the NDR your Received . your LegacyExchangeDN value might would have change when you delete and recreate . (If its a migrated mailbox) you would probaly try adding X500 Address . if you don't want to add clear your .N2K file for every machine u use If your NDR looks kind of similar to this. IMCEAEX - ######################## #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found

Keep in mind the server side update only needs to be done once, so if you've already done that then you can move on from that. In relation to the errors from Get | Update-GlobalAddressList, while you have some warnings that need to be investigated, the GAL is still updating or else you wouldn't have seen any change with the it@ address, so again, you could come back to those problems and look at them as a separate task. I don't have any bright ideas in relation to removing a single entry from an .nk2 file, unfortunately, as Outlook 2010 doesn't make use of this file anymore, meaning there's nothing for me to take a look at. Cheers, Lain

I just took a look around out of interest, and if you're got some bored folks around with C/++/# skills, take a look at these: MSDN: Nickname cache MSDN: Autocomplete stream PDF: Detail on the autocomplete stream Given there's a lot of information about it, I'm guessing there may well already be a tool around do edit either the stream (if Outlook's already open) or file (if Outlook is closed - ideal for a logon script approach). Cheers, Lain

Hi Kyle, Please take a look at this thread: http://social.technet.microsoft.com/Forums/en-US/exchangesvradmin/thread/1a819714-3f35-4109-a1a4-665e788d98dd Hope it helps.Rowen TechNet Community Support

Hi Kyle, Any update?Rowen TechNet Community Support