How member can read the PM after infraction?

[dellow]

Hello,

If an admin or modirator give a member infraction then ban this member, in this case how can the member read the PM regarding infraction while he is already banned ?
if we allow banned member to use PM system he/she may use it badly and some times maybe the member will recive infraction only becaus bad using PM so we must disallow her/him to use PM system.

I think there must be an option to give the admin the ability to allow some usergroup to only recive PM but no send.

am i right ? if so any one can help with small modification ?

Regards,