Hello guys, We have a startup with an email marketing web app, we are very rigid with our clients to not allow spammers. One of our client's wants to send a message to two million contacts and I am worried with some details. I am not worried about the time that will take to send all those messages, but I am worried about respecting the server's policies.
Today we use two dedicated servers as mailservers, each one with four IPs. I want to make some benchmarks to check if we need more and how many. We use different transports according to the domain, but what limits it's sending rate is *transport_destination_rate_delay *that is a fixed value, and also we use the *transport_destination_concurrency_limit *with *transport_concurrency_negative_feedback *and *transport_concurrency_positive_feedback *to control the sending rates according to recipient policies. But I am worried that with this quantity of messages only this restrictions wont be able to manage the recipient's policies and our deliverability would be terrible. One problem that postfix don't deal is when an IP is blocked by an ISP, message rate should drop a lot while the IP does not get unblocked. Also when one IP gets greylisted it should stop sending to that domain or send only a few messages while greylisted. I want to ask you if is there any optimization in the configs or any postfix extensions that can help me deal with this. Thank you Pedro Axelrud http://mailee.me http://softa.com.br http://flavors.me/pedroaxl
