Grab Disconnected Mailbox from all databases:
Get-MailboxDatabase | Get-MailboxStatistics -Filter ‘DisconnectDate -ne $null’ | Export-CSV <path> -notypeinformation
Grab Disconnected Mailbox from a database:
Get-MailboxStatistics -Database DB01 | fl DisplayName, Mailboxguid > c:\temp\mailboxguid.txt
Disabling the mailbox
Disable-Mailbox -Identity “Joe Original”
Reconnecting the mailbox:
Connect-Mailbox –Identity <guid> –Database <database> –user <alias>