Perl Script for SMTP-Relay (Email) and a small admin panel

1. I need a SMTP-Relay Script where I will be able to allow users which have to authentificate with Username/ Password to send a limited amount of emails. (maybe 10.000) if needed I want to reset or change the limit for each user. 2. A little Admin Frontend where I can add/ delete users (define username, Email and password) and define the amount of emails, which they are allowed to send. I also want to add some more amount at every time. Every change should be documented. If the amount is reached, the user should be blocked and informed via Email, that the value is reached. He should also be able to check the actual available amount of emails. Overview of available/ sent emails per user. The sending of emails have to work with a external smtp relay host, where I can setup the authentification data once. Emails should not be send over a script based frontend, just with smtp-able software (Outlook, Thunderbird, Bulkmailer Software, ..)