Postfix limit number of emails send in a month/Day

Is it possible to limit the users to send total email in a month/day. I am trying to enforced marketing users to send newsletter according to their assigned quota.

Example 1. [email protected]: can send only 100 emails a day & 3000 emails in a month. 2. [email protected]: can send only 200 emails a day & 6000 emails in a month.

VPS: Centos6 MTA: postfix

The tool you need is the cluebringer otherwise known as policyd. It will allow you to assign quotas of all sorts (and many other functions), and importantly, allows you to count users by more immutable criteria, like their SASLUsername, allowing you to be fairly confident that people won't be able to sneak around limits by changing sending email.