You have built your local IP blacklist for Postfix. Invested time to analyze server logs or Rspamd history to blacklist single hosts, IP addresses, or even whole networks. But how well is it working compared to public blacklists you are using? Time to see the results and get some visual insights through Munin Monitoring System.
Setup your blacklist for Munin First of all, you have to decide how to visualize the data in your graph.
By running a Postfix mail server, you need to know some commands to manage Postfix mail queues. With this knowledge, you can manage queues and write simple scripts to accomplish larger tasks.
First, I will list the most relevant commands you need for your daily business. Then we will build up real-life examples to understand how these commands work, how to use them, and when they can harm.
Postfix Mail Queue Commands Postfix has several commands to manage the queues.
You know those same hosts, providers, or whole networks, who get through your spam filter and spam your users with the same content over and over again. By building up your blacklist in Postfix, you can stop them from bothering you and your users. We will explain how local blacklists work in Postfix and how to use them with whitelists to have better control and reduce errors.
Check before you blacklist Blocking other hosts must be a well-thought decision because blocking single hosts, IP addresses, or even whole networks will stop all delivery attempts to your mail servers.
If you use any blacklists for email services, whitelisting important Hosts, single IP Addresses, and even whole networks is an essential task. By whitelisting valuables email services to your users or even customers, you as admin won’t reject important email communication.
Blacklisting in Postfix If you use any blacklist service or has your blacklist in your Postfix setup, you will probably find similar logs:
root@server $ grep "blocked using" /var/log/mail.log Dec 17 4:07:18 server postfix/smtpd: NOQUEUE: reject: RCPT from unknown[1.
Monitoring email queues on your favorite email server is an essential task of an email admin, as rising queues are often an indication of problems. First, you need to understand how queues work, manage them, and get emails enqueued. Then build a shell script to monitor them. In the last step, you will learn how to get smartphone push notifications by sending emails to a third-party push service.
Queue Basics Sending and receiving emails is by default done asynchronously.