Recently, a postfix mail server running on Ubuntu gave us the following error while trying to send an email to Bob:
Jun 16 17:02:03 gateway postfix/smtp[23522]: ED3799A0D27: to=bob@gmail.com, relay=none, delay=0.02, delays=0.01/0.01/0/0, dsn=4.4.3, status=deferred (Host or domain name not found. Name service error for name=smtp.gmail.com type=AAAA: Host not found, try again)
After several attempts like changing the protocol (inet_protocols) to IPv4 (since AAAA is an IPv6 A-record) in /etc/postfix/main.cf and so on we could not get it running.. We restored the configuration file to its original and then we restarted the service:
Introduction In today's digital age, email has become integral to our personal and professional lives. While numerous email clients are available, Gmail remains a popular choice due to its user-friendly interface and powerful features. In this blog post, we will guide you through configuring Postfix, a famous mail transfer agent…
We use docker to manage multiple instances of various tools on a server that we control. We have an Nginx server working as a reverse proxy that forwards all requests to the appropriate containers in the configuration. Sometimes, after updating the container images and recreating the containers, we get the…
When you try to connect via ssh on a domain for which you are using CloudFlare as a HTTP proxy, you will get the following error: $ ssh user@example.com ssh_exchange_identification: Connection closed by remote host You have a few options to resolve for this issue: Either connect directly to the…
