Leave him alone... you have no idea what he did for CMKX!
Here is tip:
If you accept a cheque from cmkx and its fake... even if the money appears to be in your account in 7 days and the bank claims it cleared they are lying! It actually takes a bank up to three month, to fully process it.
The bank will come back and remove any money you have in your other accounts to collect if already spent it!