[Mailman-Developers] How To change queue process method

I'm new in mailman

I had research about how fast MTA (postfix) can deliver a lot of email from mailman. The one that I want to change is queue process method from FIFO to size based(sum of domain in the list x size of email), I have a list that contain the sum of domain each mailing list. I want Mailman prefer sending email that have less domain destination and small size of email.

Can you tell me what file I have to edit so mailman can decide what email is thrown to postfix first?

Sory my english is bad