Mail is not delivered to External Contact when Send from OWA

Hi All,

 I have a user who sends email to external contact ( gmail) from outlook and the message is delivered,but when he sends the email to same contact from OWA,the message is not delivered. The NDR generated form the Server is below.The user sent his mail from coorporate account to his gmail contact.The gmail conatct of this user was first created in AD but later this contact was deleted.I beleive this might be the reason but then why the messages are getting delivered when user sends them from outlook.

Thanks in advance

Received: from EXCHMBXSRV1.xxx.xxx.xx ([fe80::7da1:fcf6:77c9:a8a4]) by
 EXCHCALSRV1.xxx.xx.xxh ([::1]) with mapi id 14.01.0218.012; Wed, 13 Feb 2013
 08:57:36 +0300
Content-Type: application/ms-tnef; name="winmail.dat"
Content-Transfer-Encoding: binary
From:
"Mohammad  Younis" Younis@xxx.xx.xx
To: Mohammed Younis gmailIMCEAEX-_O=FIRST+20ORGANIZATION_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=Mohammed+20Younis@xxx.xx.xx
Subject:
Thread-Index: Ac4JrwUwWdKIus1zSTS+rxhX89j53Q==
Date: Wed, 13 Feb 2013 08:57:35 +0300
Message-ID: A1F7D1BA8B0D084E83395F20B4318BB909D20393@EXCHMBXSRV1.xxx.xxx.xxx
Accept-Language: en-US, ms-BN
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator: A1F7D1BA8B0D084E83395F20B4318BB909D20393@EXCHMBXSRV1.xxx.xxx.xx
MIME-Version: 1.0
X-Originating-IP: [10.19.18.34]

EagleAsh