Hi Running Exchange 2007 SP2/Outlook 2007 SP2. We had a mailbox, redman.surname@domain.com, that was deleted. A week later, it was recreated. Problem is, some people are having problems emailing this address now if they are using their cache entry in Outlook. DSN is: IMCEAEX-_O=DOMAIN_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=redman+2Esurname@domain.com #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ## I have created the new mailbox on exactly the same store it was on before. Reading article here (http://www.simple-talk.com/content/print.aspx?article=628), I need to add the X.500 address of the old mailbox to as an X.500 to the new mailbox. But what is the X.500 address here I need to add?

Correct when you delete and recreate the mailboxes all settings are lost. You need to add this x500 address. Go to the email address tab of the user, add custom address, since you transposed your actual domain replace it with your actual domain. Add it exactly like below. /o=Domain/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=redman.surname Also you can look at another mailbox user, email address tab and see if they have x500 addresses and you can look at the naming convention. James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Hello James Thanks, but we have recreated the mailbox/AD account in the same location so shouldn't the LegacyExchangeDN still be the same? The Alias is the same. That's why I don't understand why we are getting these error messages. How can I see the LegacyExchangeDN of the new mailbox, what command would I need to run in Powershell? Secondly, the address in the DSN looks strange doesn't it? IMCEAEX-_O=DOMAIN_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=redman+2Esurname@domain.com #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ## Why the "redman+2Esurname@domain.com" bit?

The legacyExchangeDN may not necessary be the same, typically it's the same but there's instances where the legacyexchangedn was not in the correct format, sometimes it can get created like /o=Domain/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=redman.surname748343 (note the random numbers) This can occur during migrations or different scenarios. Don't assume that it's the same as before. It's in ascii format redman+2Esurname@domain.com = redman.lastname 2E is a period in ascii also don't append @domain.com when creating the x500James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Ok, makes sense :) So, if the DSN was this: IMCEAEX-_O=DOMAIN_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=redman+2Esurname@domain.com #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ## Could you confirm the -exact- X.500 address I should add to the new mailbox to allow cached Outlook entries to send email to the new mailbox?

Yes it would be /o=Domain/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=redman.surname It lookes like you mask the domain so you need to substitute with whatever the true value is.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Thanks James.. Couple of further questions: i. The DSN has the @domain name in the X.500 address (O=DOMAIN_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=redman+2Esurname@domain.com) Yet, generally legacyExchangeDN's don't have an @. Do you know why the DSN contains it? ii. I assume i need to add the address you say as a "CUSTOM" address, specifying "X500". Once that is done, should I then be able to send to that X500 address using Outlook? How long until Outlook is aware of it?

I'm assuming the connector appends @domain.com it during transport, but can't confirm. Yes once you add it it will work almost right away. You can also test it by directly emailing the x500 address. Open outlook and in the to field enter exactly like below. If you don't get NDR right away you're good. O=DOMAIN_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=redman+2Esurname@domain.comJames Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Hi, How can I see the LegacyExchangeDN of the new mailbox, what command would I need to run in Powershell? In order to see and modify LegacyExchangeDN, you could use the LegacyExchangeDN tool. You can download it from here: http://www.microsoft.com/downloads/en/details.aspx?familyid=5ef7786b-a699-4aad-b104-bf9de3f473e5&displaylang=en As we known , the Exchange Recipient Update Service (RUS) is responsible for filling the LegacyExchangeDN attribute. There are some different between Exchange 2003 and Exchange 2007. In Exchange 2003 the recipient update service (RUS) would scan the directory for object changes based on the objects USN In Exchange 2007 and Exchange 2010 the RUS has become a process initiated by a task rather than scanning the directory for changes. By default when any task is run that alters a user object, such as set-mailbox or set-user, the recipient update service is called by the task. So after you modify LegacyExchangeDN, please run the command “ set-mailbox” More information about Exchange 2007 / Exchange 2010 recipient update service http://blogs.technet.com/b/timmcmic/archive/2010/03/22/exchange-2007-exchange-2010-interesting-recipient-update-service-issue.aspx You also can resolve the issue at client side. You just need to delete the cached entry from NK2 file. For how to delete an entries from nk2 file: http://support.microsoft.com/kb/287623Please 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.