bug on 7.5.3

[atomicmak]

i am running latest 7.5.3 and i've found bug on it.

i have allowed 5 email to be create in domain and domain administrator can able to create unlimited emails.

after one customer told me this i've checked with some other domain and it allows to create more than the email allowed to create.

anyone here aware of this and anyone have any solution for this bug ?