The MS Excel's insert column option is disabled...

The following steps resolve the issue

1. Close all open Excel windows
2. In Windows Explorer, go to directory "%appdata%\Microsoft\Excel"
3. Rename the file:  Excel15.xlb --> Excel15.old

Exchange 2013/2010 mailbox backup by export to PST (PowerShell)

Single mailbox export to PST file

Exporting mailbox contents to a PST file is achieved using the MailboxExportRequest cmdlet. It has only 2 obligatory parameters: –FilePath – defines the network share path of the PST file to which you want to export the data; and –Mailbox – defines the Alias, SMTP address or Display name of the mailbox you will export.Requirements:

• The user performing the export must be a member of a role group which has the Mailbox Import Export role added. The easiest way of achieving this is running this script:

  New-ManagementRoleAssignment -Role "Mailbox Import Export" -User "<user name or alias>"
• The location to which you will export the PST file must be a shared folder.

Syntax

Here is an example of a mailbox export request, which backs up an entire mailbox to a PST file:

New-MailboxExportRequest -Mailbox <user> -FilePath \\<server FQDN>\<shared folder name>\<PST name>.pst