Add X500 Alias to Mailboxes with Old LegacyExchangeDN Value

Scenario: A user receives a bounce message (Non Delivery Report/NDR) when emailing to an internal user that contains the following:

 

Delivery has failed to these recipients or groups:

John Test<mailto:IMCEAEX-_O%3DYOUR%2B20ENTERPRISE%2B20EXCHANGE_OU%3DEXCHANGE%2B20ADMINISTRATIVE%2B20GROUP%2B20%2B28FYDIBOHF23SPDLT%2B29_CN%3DRECIPIENTS_CN%3DJTest451a@domain.edu<mailto:3DJTest451a@domain.edu>>
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.

Cause: This issue occurs because the value for the LegacyExchangeDN attribute changed. The auto-complete cache in Microsoft Outlook and in Microsoft Outlook Web App (OWA) uses the value of the LegacyExchangeDN attribute to route email messages internally.

 

Resolution: Global Fix - Creating an X500 address based on the LegacyExchangeDN and adding it as an email alias to the recipients Exchange mailbox.

Copy/Extract the LegacyExchangeDN info from the NDR. This is located under the Generating Server portion. It looks like this:

IMCEAEX-_O=YOUR+20ENTERPRISE+20EXCHANGE_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=JTest451a@domain.edu

 

Perform the following on that address:

•Replace any underscore character _ with a slash character /
•Replace +20 with a blank space.
•Replace +28 with an opening parenthesis character (.
•Replace +29 with a closing parenthesis character ).
•Delete IMCEAEX-.
•Delete @domain.edu.

Final Result: /O=YOUR ENTERPRISE EXCHANGE/OU=EXCHANGE ADMINISTRATIVE GROUP (FYDIBOHF23SPDLT)/CN=RECIPIENTS/CN=JTest451a

 

Take the final result and add this as an X500 alias for the receiving mailbox by performing these steps:

1. Open the properties of the affected mailbox in Exchange 2010.

2. Click on the Email Addresses tab.

3. Click the drop down menu next to Add... and select Custom Address.

4. In the Custom Address properties window:

i. Email Address: /O=YOUR ENTERPRISE EXCHANGE/OU=EXCHANGE ADMINISTRATIVE GROUP (FYDIBOHF23SPDLT)/CN=RECIPIENTS/CN=JTest451a

ii. Email Type: X500

5. Click OK out of all the mailbox windows and you are done.

 

Testing: You should be able to enter in the X500 into a new mail message and perform a check names. It should resolve to the users account.

 

 

Notes

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• This can be performed on the server to apply a global fix. The real issue is stemming from the 'Type Ahead' cache in the users Outlook/Outlook Web App. They can easily clear out the cache completely OR delete the type ahead address as they are entering it and reselect from the address book..
• Reference: The Cause and Resolution have been taken and modified to fit our scenario from here.