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:
 
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


Out of Office Not Working for a Single User

Issue: Out of Office is turned on for a user, but a Out of Office notification is not beingsent to internal/external users. You may see the Out of Office message internally BEFORE you send the message in the Outlook notification bar in the new message window.

Cause: Mailbox rules have corrupted or are conflicting with the Out-Of-Office rule in order to send a message to recipients.
Resolution: The resolution is to remove the conflicting rules in the mailbox. To do this:
1. From a run prompt use the following switch: outlook.exe /cleanrules .This will clean client and server rules for the mailbox. This is the fastest way of fixing this issue.
2. You can manually remove each rule in the mailbox.