postfix connection refused - Postfix mail server connection refused

root@linuxfix:~/postfix_connection_refused$

postfix connection refused

Postfix mail server connection refused

Solutions

Prerequisites: Start by updating your system to resolve common issues and ensure the solutions provided below are compatible with your current environment.

check_latest_version && sudo apt update && sudo apt upgrade -y

Start Postfix service

Start mail server:

sudo systemctl start postfix

sudo systemctl status postfix

sudo postfix start

Check configuration

Verify Postfix config:

sudo postconf -n

sudo postfix check

postconf mail_version

Test SMTP connection

Test mail server:

telnet localhost 25

echo "test" | mail -s "test" user@domain.com

mailq

What is postfix connection refused?

Postfix mail server is not accepting connections on SMTP port.

Common scenarios: Service not running, firewall blocking, or configuration issues.

Common Causes

Postfix service stopped
Firewall blocking port 25
Configuration errors
Port binding issues
Authentication problems

Debugging Tips

tail -f /var/log/mail.log

netstat -tlnp | grep :25

ps aux | grep postfix

Prevention

Monitor mail service
Regular config validation
Log monitoring

Additional Resources

Postfix Documentation

Postfix mail server guide

postfix mail smtp email