Is your Postfix server showing error message ‘connection refused’?

Usually, this can occur due to reasons like port block, firewall restrictions, bad configuration, etc.

At Bobcares, we often get requests to fix Postfix errors, as a part of our Server Management Services.

Today, let’s have a deep look at how our Support Engineers make Postfix working.

Postfix error connection refused

Mail Transfer Agent or MTA has an important role to play in mail transfer. That is, routing the mails. Postfix is one of the popular mail transport agents.

Many times, the user access to the Postfix server fails. And a typical error message appears as

postfix[23093]: connect to mail.domain.com[ip address]: Connection refused (port 25)

Here, access to the server through port 25 refuses the connection.

How we fix the connection refused error?

At Bobcares, where we have a decade of expertise in managing servers, customers often approach us with Postfix connection refused error. Let’s see how our Support Engineers fix this.

1. Check the Postfix server status

Whenever the server shows a connection refused message, we initially check the server status. This is because the most possible reason can be an inactive server.

In this case, our Support engineers check the Postfix server status. Then we restart it if needed.

2. Network configuration

Another possible reason can be with the domain resolution. So we check if the domain is resolving or not. Then if any problem persists we start fixing it and make the domain resolvable.

3. Improper configuration

Some customers need remote host access to the Postfix server. So, we need to add this to the default configuration. Our Support Engineers edit the Postfix config file, main.cf. This file contains the basic connection configuration of the server.

inet_interfaces = all

mynetworks_style = subnet

mynetworks = xx.xx.xx.xx,xx.xxx.xx.x

Add the remote IPs in mynetworks. Then in the master.cf file we edit,

0.0.0.0:smtp inet n - n - - smtpd

Finally, we restart the Postfix service.

4. Firewall restrictions

Also, firewall rules can block both port and remote IP from accessing the server. So our Support Engineers check if the firewall rules are leading to the error or not. Here, we confirm that the mail ports like 465, 25, etc. are open in the server.

[Need assistance in fixing Postfix errors? – We’ll help you.]

Conclusion

In short, the Postfix connection refused error occur due to reasons like firewall restrictions, inactive servers, misconfiguration and so on. This error also shows up when accessing the server through a remote IP. Today, we saw how our Support Engineers fix this error.