Users getting delivery failed when sending to a specific user

check if this is of any help
http://support.microsoft.com/kb/556074

I went through this solution.

And I did not find anything wrong with the legacyExchangeDN attribute on the user.

can u paste the legacydn here?

the legacydn looks like this.

/o=OrganizationName/ou=First Administrative Group/cn=username

not going to post the actual info for work reasons

Here is also the undeliverable report


Diagnostic information for administrators:

Generating server: email.domain.com

UserA@domain.com
#550 4.4.1 STOREDRV.Deliver: connection timed out. The following information should help identify the cause: "MapiExceptionUnableToComplete:16.18969:DD1D0000, 17.27161:000000005E020000000000006D00000000000000, 255.23226:00000000, 255.27962:7A000000, 255.27962:0A000000, 255.27962:0E000000, 255.27962:0A000000, 255.27962:0C000000, 255.17082:00040480, 0.18273:2B000000, 4.21921:00040480, 255.27962:FA000000, 255.1494:0F010480, 255.1238:0F010480, 6.21970:0F01048002018A670F010480, 4.23921:EC030000, 6.21970:0F0104800300F1670F010480, 6.21970:0F010480020185670F010480, 6.21970:0F01048040008F66E7FAFFFF, 6.21970:0F01048002018667E7FAFFFF, 6.21970:0F01048040008F660F010480, 6.21970:0F010480020186670F010480, 6.21970:0F01048040008F660F010480, 6.21970:0F010480020186670F010480, 4.8916:E7FAFFFF, 4.14219:E7FAFFFF, 4.15243:E7FAFFFF, 4.12427:E7FAFFFF, 4.5312:0F010480, 6.21970:0F010480008013360F010480, 4.31473:0F010480, 6.21970:0F010480008013360F010480, 4.31473:0F010480, 4.6926:00040480, 255.1750:EF7B0000, 255.31418:9D000000, 0.21457:00000000, 4.19665:00040480". ##

Original message headers:

Received: from email.domain.com ([::1]) by email.domain.com ([::1])
 with mapi; Thu, 6 Oct 2011 11:20:12 +0000
Content-Type: application/ms-tnef; name="winmail.dat"
Content-Transfer-Encoding: binary
From: =?utf-8?B?SMO2csOwdXIgU3ZlaW5zc29u?= <userb@domain.com>
To: Username <usera@domain.com>
Date: Thu, 6 Oct 2011 11:20:11 +0000
Subject: =?utf-8?B?ZmxlaXJpIHByw7NmdW5hciBmdW5kYXJib8Ow?=
Thread-Topic: =?utf-8?B?ZmxlaXJpIHByw7NmdW5hciBmdW5kYXJib8Ow?=
Thread-Index: AcyEGeluPwzqvrT4SkKwfeKY8ZFI0w==
Message-ID: <DD328785B4A88946B613523D969D956E245B6C64BE@email.domain.com>
Accept-Language: en-US, is-IS
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator: <DD328785B4A88946B613523D969D956E245B6C64BE@email.domain.com>
MIME-Version: 1.0
X-TM-AS-Product-Ver: SMEX-10.0.0.1412-6.800.1017-18400.003
X-TM-AS-Result: No--32.275800-0.000000-31
X-TM-AS-User-Approved-Sender: Yes
X-TM-AS-User-Blocked-Sender: No

As per bounce mail its showing timeout error. just dismount the database and remount it also try to reboot your server. please also tell us about your exchange design if it is in clustering or what. there may be some permission issue also ..

there is no clustering.

It is just a single Exchange 2007 server

I did the reboot and that had no effect.



I will try the dismount and re-mount of the database next.