Outlook 2010 Cached Mode Unable to Send Email to External Recipient


  • We are currently experiencing random email issues with users unable to send messages to external recipients when in Outlook Cached Mode. The problem is completely random. When we place the user’s Outlook client into Online Mode, they have no issues. Can someone assist me with this issue?


    Error Message:


    The operation failed. The messaging interfaces have returned an unknown error. If the problem persists, restart Outlook, Cannot resolve recipient.

    Wednesday, November 16, 2011 3:18 PM


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