Scenario: When issuing a new move request, you receive the following error:
Mailbox Size <size> exceeds target quota <size>
Solution: Temporarily lift the ProhibitSendReceive quota size and run the new move request again. You can set the ProhibitSendReceive quota to unlimited OR to a higher value than the current mailbox size.
Get-mailbox <alias> | Select Prohibit*
Set-mailbox <alias> -prohibitsendreceive unlimited.
If the mailbox is 50MB, you could also run this:
Set-mailbox <alias> -prohibitsendreceive 55MG.
Ex-Shell 