Here are a few troubleshooting tips to solve the “Sendmail deferred connection refused by 127.0.0.1” error. Our Sendmail Support team is here to help you with your questions and concerns.

Sendmail deferred connection refused by 127.0.0.1

Some of our customers recently faced a bit of trouble when they kept coming across the following error message when they tried to send an email with a Sendmail command on a Unix or Linux-based operating system.

Sendmail deferred connection refused by 127.0.0.1

According to our experts, this error message indicates that the IP address 127.0.0.1 has refused the connection to the mail transfer agent on the local system. The IP address 127.0.0.1 is also known as the “localhost” IP address. In other words, this IP address is used to refer to the local machine.

This specific error may arise due to several reasons. let’s take a look at some of the commonly seen reasons:

• The mail transfer agent or MTA may not be running on the local system. In this scenario, it will not be able to receive email messages and hence will refuse the connection.
• In case the MTA is not configured correctly, it will lead to the error message “ Sendmail deferred connection refused by 127.0.0.1:.
• If a firewall or port blocking rule prevents the connection to MTA, we are likely to come across the error message.
• If the MTA is configured to use DNS to resolve hostnames, in some cases it is able to resolve the local system’s hostname. This can cause the connection to be refused.

Troubleshooting Tips

Our experts have together the following troubleshooting tips to resolve this error:

• To begin with, check the MTA is running and configured correctly.
• Next, ensure the firewall or port blocking rules do not prevent MTA connections.
• Then, check the DNS settings are correct, and the MTA can resolve the hostname for the local system.

Let us know in the comments if these troubleshooting tips helped resolve the error.

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Conclusion

To conclude, our Support Techs demonstrated how to resolve the “Sendmail deferred connection refused by 127.0.0.1” error with different troubleshooting tips.