I am using Postfix for send about 20 000 – 30 000 e-mail per day. For messages not ended into a spam, the script is running with 1 second break every email send. As a result, e-mail are sending about 5 - 8 hours.
When an error occurs on the server (for example network goes down), script is still running and Postfix queues emails. When network connection come back, Postfix try to send unsent e-mail at once, about 30 emals per second.
Is there any parameter for Postfix which would allow for a slowdown sending queues e-mails?