Hi. I am in MS Exchange 2010 and Outlook environment.  Meghan's email bounces back when she tries to email Kim who is on the same GAL but different domain. I am on the same domain as Meghan and I can email Kim without a problem.  Both Meghan and I can email user Nadia. Nadia is on Kim's domain.  

So we know it is a Meghan to Kim problem.  Meghan can receive email from all of us without problem. 

We have cleared the cache (deleted .nk2). even had her try 'reply' from her work email on her phone instead of the computer. Meghan tried to reply directly to Kim's email without luck;  

Why is Meghan not able to email Kim?

Here is one of the error messages received (modified to secure users name and domain names):

Delivery has failed to these recipients or groups:

Cxxxx, Kimberly - (XYZ City)

There is a problem with the recipient's e-mail system. More than one person has this e-mail address. The recipient's system administrator will have to fix this problem.

Diagnostic information for administrators:

Generating server: retexch001.ABC.ORG

IMCEAEX-_O=RETEXCHANGE_OU=First+20Administrative+20Group_cn=Recipients_cn=KCxxxx@SenderDomain.ORG

#550 5.1.4 RESOLVER.ADR.Ambiguous; ambiguous address ##

Original message headers:

Received: from retexch001.RETLAN.ORG ([192.168.65.223]) by retexch001

([192.168.65.223]) with mapi; Mon, 18 May 2015 14:06:41 -0400

Content-Type: application/ms-tnef; name="winmail.dat"

Content-Transfer-Encoding: binary

From: "Hxxx,Meghan"

To: "Cxxxx, Kimberly - (XYZ City)"

Subject: test

Thread-Topic: test

Thread-Index: AdCRlYTa1xuvVwAIScC55l+TmE/cGQ==

Date: Mon, 18 May 2015 14:06:40 -0400

Message-ID: <501C5C4BAC2989498C40F198DE8185A50DE8E2BF@retexch001>

Accept-Language: en-US

Content-Language: en-US

X-MS-Has-Attach:

X-MS-TNEF-Correlator: <501C5C4BAC2989498C40F198DE8185A50DE8E2BF@retexch001>

MIME-Version: 1.0

Ok it seems there are two objects with similar mail address,

go to adsiedit.msc create a query for mail=recipientaddress and see how many objects have these email address, remove which is not required and it should fix the issue

i faced this issue before, there was another mailbox has the same value "legacyExchangeDN"

from Active directory users and computers > enable advanced features from view, get the target user (not by search) and properties check the attribute editor "legacyExchangeDN" value 

check and feed me back..

Here is the result from legacyExchangeDN" value:

/o=RETEXCHANGE/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=Hxxx,

Hi,

There is a problem with the recipients e-mail system. More than one person has this e-mail address that is duplicate email address issue like another user having the same x500 legacy values in another user mailbox 

Legacy Value: "O=RETEXCHANGE_OU=First+20Administratve+20Group_cn=Recipients_cn=KCxxxx@SenderDomain.ORG"

Please find the another user mailbox as below.

1.From the error please check who are having same SMTP ID matching.

2.From the dsa.msc please search custome wise like below object types.
(&(objectCategory=*)( proxyaddresses=smtp:something@somewhere.com))

3.Export all SMTP and legacy values for all users and find which mailbox having the legacy value and remove it then include legacy values to approprite mailbox.

For you referance please find the below URL's

1.http://theucguy.net/550-514-resolveradrambiguous-ambiguous/
2.http://msexchangeguru.com/2012/03/15/x500/

Regards,

Kumar N

Hi. I was looking at the legacyExchangeDN value again.  Should the "/o=RETEXCHANGE" portion be "/o=<servername>"?  RETEXCHANGE is the name of our old Exchange server.  However, my personal account also has that and I can send email to Kim. So that is not the problem but I was just aski

Hi

could you post the delivery failure message?

or is this it:

"Delivery has failed to these recipients or groups:

Cxxxx, Kimberly - (XYZ City)

There is a problem with the recipient's e-mail system. More than one person has this e-mail address. The recipient's system administrator will have to fix this problem."

also are you using offline address book or online?

Hi Jim,

Please see answers to your questions below:

• Have you try to logon by OWA on different client using Meghans account to check if we could send emails to Kim?
  Meghan gets her office emails on her phone also. She did use her phone to "reply" to an email she received from Kim. Is the phone attempt as good as OWA? This email also did not go.
• Did Kim email to Meghan? Kim "replied all" to an email I sent to both Meghan and Kim.  Megan did get the reply.  This is the same email Megan replied to as mentioned above.
  
  
  

Hi Bamedele,

Use the following link to export Meghan and Kim s AD user property and send them to ibsexc@microsoft.com for our troubleshooting.

https://gallery.technet.microsoft.com/scriptcenter/Getting-Users-ALL-7417b71d

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim