Hi… is it possible to disable the mysource internal e-mail system?
Yes, by manipulating the Messaging Service configuration. It depends on which messages you want to suppress, though.
What i mean is to disable the MYspace & inbox, etc.
There is no single toggle to just enable/disable the Inbox. What you can do is disable certain messages from being sent to that Inbox. I suggest contacting Squiz Support so that they can work with you to configure the messaging service appropriately.