SMTP limiter

[cyber2]

Hi guys,
How to limit the number of emails per hour/day from one user/domain into ispCP? (as like as SMTP limiter plugin in DirectAdmin)
I'm searching this forum already, but nothing found...

And another question... why do you accept donations only via paypal? If we could make donations via Webmoney, I would be pleased to make it (as many others ex-USSR users of ispCP).

Thank you for your replies.