Receive an NDR when sending email to a new user in domain SBS2011 using clients Outlook 2010 that the desktops were previously updated from Outlook 2003 and Outlook 2007..

After extensive review looked at OAB Outlook Address Book. Outlook, Send/Receive, Send/Receive Groups, Download Address Book and after that check to see if the new user is in the OAB Outlook Address Book. In OAB but still an NDR.

Replace OAB in EMC EMC, Organization Configuration, mailbox, Offline Address Book, remove, Add new Offline Address Book,. Mailbox, Database Management, Mailbox Database , client Settings, Browse for public folder and OAB browse for OAB

Still fails. Error is we get NDR #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##

We logged onto computer as a user, and attempt to download OAB and get error 0X8004010F. Eventvwr does not show any issues with OAB generator of msexchangesa. We checked and found user’s account to be using the emails address policy as set. We tried to check for .nk2 cache however its a win7 Outlook 2010 client. We deleted user that was ndr from the cache, now we are able to send email to that user now, and once we do that, OAB correctly autocomplete that user’s account.

We tried to use Outlook.exe /CleanAutoCompleteCache on one of the client machines, it did fix the issue.

it seems that OAB had incorrect info for user that was causing ndr, we did recreate OAB however since most client machines are in cached mode, they didnt get fixed, hence we need to clean auto complete cache, or remove OL from cached mode and they enable cached mode again so that the the autocomplete feature to correctly work.

Example of error

Delivery has failed to these recipients or groups:

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.

Diagnostic information for administrators:

Generating server: SBS2011.domainname.local

IMCEAEX-_O=domainname_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=user2@domainname.com

#550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ##

Original message headers:

Received: from SBS2011.domainname.local ([fe80::504a:b435:e69f:ca1e]) by

SBS2011.domainname.local ([fe80::504a:b435:e69f:ca1e%10]) with mapi id

14.01.0339.001; Mon, 5 Mar 2012 14:30:09 -0800

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

Content-Transfer-Encoding: binary

From: user1 <user1@domainname.com>

To: user2 <user2@domainname.com>

Subject: TEST

Thread-Topic: TEST

Thread-Index: Acz7H4RetpKjGzCTST2m41lY9NZuOA==

Disposition-Notification-To: user1 <user1@domainname.com>

Date: Mon, 5 Mar 2012 14:30:07 -0800

Message-ID: <D57F9D5A4AA3BB418C8655D1A6EC71B606425FA4@SBS2011.domainname.local>

Accept-Language: en-US

Content-Language: en-US

X-MS-Has-Attach:

X-MS-TNEF-Correlator: <D57F9D5A4AA3BB418C8655D1A6EC71B606425FA4@SBS2011.domainname.local>

MIME-Version: 1.0