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Exchange 2010/2016 Coexistence. Cannot open mailboxes using Outlook installed on mail server RRS feed

  • Question

  • I have a strange one... We recently spun up 3 new Ex2016 Std servers (2x prod and 1x DR) and have 2x Ex2010 servers in coexistence. I've been trying to set up Commvault backups and have run into a fun issue.

    When running Outlook 2013 or 2016 locally on the Ex2016 mailserver and trying to open an Ex2016 mailbox (Ex2010 mailboxes open fine) I receive the following error:

    "Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintenance."

    All mailboxes open without issue from other endpoints. I can also open any Ex2010 mailbox from the Ex2016 mailserver without issue. Our Ex2010 servers and Ex2016 CAS arrays are in separate namespaces and we're not having any other troubles.

    Assistance would be greatly appreciated.

    Thursday, August 17, 2017 8:29 PM

All replies

  • I have a strange one... We recently spun up 3 new Ex2016 Std servers (2x prod and 1x DR) and have 2x Ex2010 servers in coexistence. I've been trying to set up Commvault backups and have run into a fun issue.

    When running Outlook 2013 or 2016 locally on the Ex2016 mailserver and trying to open an Ex2016 mailbox (Ex2010 mailboxes open fine) I receive the following error:

    "Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintenance."

    All mailboxes open without issue from other endpoints. I can also open any Ex2010 mailbox from the Ex2016 mailserver without issue. Our Ex2010 servers and Ex2016 CAS arrays are in separate namespaces and we're not having any other troubles.

    Assistance would be greatly appreciated.

    Why did you install outlook on the Exchange Server?

    Thursday, August 17, 2017 9:23 PM
  • Outlook is required to be installed on the server for Commvault mailbox backups.
    Thursday, August 17, 2017 9:32 PM