Why my host name is unqualified on Sendmail? At Bobcares, with our Server Management Services, we can handle your server-related issues.

Why my host name is unqualified on Sendmail?

Sometimes even after we set up sendmail properly, we may not be able to send emails. The following error may appear:

The most common signs include Sendmail being extremely glitchy or hanging entirely. From the error notification itself, we’ll get an idea of what causes the error. The meaning of the unqualified host name shows that Sendmail cannot resolve the fully qualified domain name.

Troubleshooting

In order to troubleshoot the issue, we’ll look into the below steps:

1. Find our host name using the hostname command.

$ hostname

2. Look into the content of /etc/hosts file. If the host is not FQDN, we’ve to modify /etc/hosts to fix the issue as given below.

127.0.0.1       localhost

127.0.1.1       name of our FQDN

127.0.0.1       localhost.localdomain localhost name of our FQDN

127.0.1.1       name of our FQDN

3. Now restart the sendmail service. Then try sending the email again.

$ sudo systemctl restart sendmail

Even with this update, if the fully qualified domain name is not correctly configured, it is doubtful that the email will be delivered. This is a prerequisite that needs to be set up before sendmail will function.

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Conclusion

To conclude, we’ve provided the steps from our Tech team to fix the unqualified host name issue in Sendmail.