I have an environment which contains Exchange 2010 mailbox server and Exchange 2013 backend server. From Exchange 2013 Management Shell, I run "New-MailboxSearch" cmdlet , and specify ONLY 2013 mailbox in '-SourceMailboxes' parameter, NO 2010 mailbox. After several hours, I check this search status by run "Get-MailboxSearch", it always be "queued". No matter how long time past, it status won't change. So I have to stop and remove this search.
And I tried eDiscovery in 2013 ECP, it comes the same result, task status is "queue" forever.
But in another environment which contain only Exchange 2013 server, "New-MailboxSearch" runs very well.
Can I search 2013 mailbox in 2010 and 2013 hybrid environment?