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"550 5.6.0" NDR and duplicated attachments when an encrypted email is sent in Outlook in Exchange Server 2013


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Symptoms

In a Microsoft Exchange Server 2013 environment, when you send or forward an S/MIME protected email that contains attachments in Microsoft Outlook in Online Mode, the attachments of the email may be duplicated. Additionally, when you send the S/MIME email to external recipients, you may receive a non-delivery report (NDR) that contains the following error message:
Remote Server returned '550 5.6.0 M2MCVT.StorageError.Exception: ConversionFailedException, Content conversion: Invalid S/MIME encrypted message.; storage error in content conversion.

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Cause

This issue occurs because a property that's related to attachments isn't returned properly by Exchange server 2013 when Outlook is in Online Mode.

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Workaround

To work around this issue, set your Outlook 2013 account to Cached Exchange Mode.

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Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

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Keywords: kbqfe, kbsurveynew, kbfix, kbexpertiseinter, kb

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Article Info
Article ID : 3087293
Revision : 1
Created on : 1/7/2017
Published on : 9/15/2015
Exists online : False
Views : 368