Hello Any help with this issue would be greatly appreciated. About a week ago we had a system drive failure that cause our exchange server databases to be corrupted. After restoring the databases and getting the system stable again we began to have an issue with accepting calendar invites from addresses outside of our domain. The calendar invite comes into the users mailbox and is added to the calendar but if you choose to accept the invitation and reply you get an undeliverable message back from our hub/transport server. Anyone have any ideo what would cause this issue or how to fix it? Thanks again. Delivery has failed to these recipients or distribution lists: The e-mail system had a problem processing this message. Microsoft Exchange will not try to redeliver this message for you. Please provide the following diagnostic text to your system administrator. Sent by Microsoft Exchange Server 2007 Diagnostic information for administrators: Generating server: XXXXXXXXXXX xxxxxx@xxxxxx.com #550 5.6.0 M2MCVT.StorageError; storage error in content conversion ## Original message headers: Received: from xxxxxx.xxxxxxx.xxxxx ([fe80::e533:3bc:7ee3:ac5f]) by xxxxx.xxxxx.net ([::1]) with mapi; Mon, 29 Nov 2010 11:28:19 -0500 Content-Type: application/ms-tnef; name="winmail.dat" Content-Transfer-Encoding: binary From: xxxxxx xxxxxxxxx xxxxx@xxxxxx.xxxxx To: "xxxxxx@xxxxxx.com" <xxxxxxx@xxxxxx.com> Date: Mon, 29 Nov 2010 11:28:18 -0500 Subject: Accepted: Invitation: test @ Mon Nov 29 11:30am - Thu Dec 2, 2010 9:30am (xxxxxx@xxxxxx.xxxxxxxx) Thread-Topic: Invitation: test @ Mon Nov 29 11:30am - Thu Dec 2, 2010 9:30am (xxxxx@xxxxxx.net) Thread-Index: AcuP4m4g+IMh2HznT+W8um4SW09cNA== Message-ID: <730D05322131874E80B8289245165019028FB590@xxxxxx.xxxxxxx.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: 730D05322131874E80B8289245165019028FB590@xxxxxxx.xxxxxx.net MIME-Version: 1.0

AV, antispam or something scanning SMTP traffic would be my guess. Calendar invites from the Internet are always hit and miss anyway, and the above are the usual reason why. The additional information required can be broken easily. There is the classic winmail.dat in your error - Google that and you will have a couple of million hits. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources