At '%8', database copy '%1' on this server wasn't able to mount because the number of mailbox database copies on this server ...

At '%8', database copy '%1' on this server wasn't able to mount because the number of mailbox database copies on this server exceeds the configured limit. The error returned was "%7".  For more information, consult the Event log for "ExchangeStoreDb" or "MSExchangeRepl" events.