Two recipients are configured with the same e-mail address
This often happens where we get NDR 5.1.4 stating “Two recipients are configured with the same e-mail address” in Exchange.
From: System Administrator
Sent: Wednesday, February 21, 2010 4:22 AM
Subject: Undeliverable: Delivery Status Notification (Failure)
Your message did not reach some or all of the intended recipients.
Sent: 2/21/2010 4:22 AM
The following recipient(s) could not be reached:
Lastname, Firstname on 2/21/2010 4:22 AM
A configuration error in the recipient’s e-mail system prevented delivery of this message. Two recipients are configured with the same e-mail address. Contact your administrator.
The LegacyExchangeDN of the user is not pointing to the correct user ID/NT ID.
How to resolve:
Open ADSIEdit.msc, Expand Domain Partition and navigate to the path where the user resides.
Goto the properties of the user and look for the attribute “legacyExchangeDN”.
Open it and see if the user’s NT ID is displayed at the end.
Edit and change it and wait for replication.