We run two Postfix servers that handle thousands of messages an hour for hundreds of customers. The Postfix servers pipe messages into a PHP script that can sometimes take 1-2 minutes to fully run (this is okay).
When we are hit with a lot of messages in a short time from a single customer, we find that our queues are backed up and messages from other customers may be delayed as much as 30-40 minutes.
I'm quite adept at Postfix configuration, but I have no experience with implementing a throttling mechanism. I'd like to hire someone to consult with me via the phone and possible remotely on our server.
I'm looking for someone with experience in advanced Postfix configuration, including throttling messages. Before applying, you should have a good idea of what we should implement in order to assure that messages to @customera.com don't backlog a message for @customerb.com. Feel free to ask questions if you need more clarity.