Any income or expenses related to the IRA investment must flow through the IRA.
For real estate this includes rental income or real estate tax payments. Rent checks should be made payable to M2 Trust Services Custodian FBO (your name) (IRA account number); real estate property tax bills should be submitted to the custodian for payment from IRA.
For deeds of trust or promissory notes, principal and interest payments should be made directly to M2 Trust Services LLC. The same process should be followed for any type of income generated from passive investments in privately held companies.