I am looking for someone who has very good experience working with Postfix. We have several retail companies and airlines who want us to write an application to feed their email messages to postfix and deliver from there. The problem is, these clients have customer bases of 250,000 - 600,000 subscribers (paying) so we would like to find someone who has very extensive experience writing their own queue files for postfix to process and deliver. We do not need code written, we just need someone to help clarify the best way to write our own queue files for postfix to deliver. Thank you.