Prevent a domain account/client account from doing spam

[Filipe Miranda]

Hello,

I have a trick question...
I have several domain accounts created inside my client account.
Is it possible to know if one of these customers is using my mail server for SPAM?

For example: customer bolinha have the domain bolinha.com
He will be able to create mail accounts using Plesk to his domain.
so he creates user1@bolinha.com

Is it possible to keep track of this domain and impose a limit to the quantity of e-mails he can send at once?

Of to find out if this domain is sending spam to other people?

Is there a way to prevent that in Plesk?
Or is there a way to prevent this in the Linux server?

Thank you,

Regards,
Filipe Miranda