Let us learn how to resolve the error dsn=5.0.0 stat=service unavailable sendmail with the support of our Server management support services at Bobcares.

Error: dsn=5.0.0 stat=service unavailable sendmail

In the context of Sendmail, the error message “dsn=5.0.0 stat=service unavailable” indicates that the mail delivery service is now offline or unable to process the sending of the email.

This error usually happens when the external SMTP server is having problems or is not properly setup.

Error Breakdown: dsn=5.0.0 stat=service unavailable sendmail

The following is a breakdown of the error message components:

1. dsn=5.0.0: “dsn” :

   stands for Delivery Status Notification and shows the email’s delivery status. The “5.0.0” indicates a permanent failure, suggesting that it cannot send the email.
2. stat=service unavailable:

   The “stat” field contains more information about the delivery status. It implies that the service required for email delivery, such as the external SMTP server, is currently unavailable in this circumstance.
3. stat=service unavailable:

   The “stat” field contains extra information about the delivery status. In this scenario, it implies that the service required for email delivery, such as the external SMTP server, is now unavailable.
4. sendmail:

   This is the Sendmail MTA (Mail Transfer Agent), which is the program that sends the email.

Causes for the Error: dsn=5.0.0 stat=service unavailable sendmail

The following are some possible causes of this error:

1. Temporary server issue:

   Due to maintenance, excessive load, or other technical issues, the remote SMTP server may be momentarily unavailable. In such circumstances, the mistake is usually just transitory, and retrying email delivery after a while may remedy the problem.
2. Misconfigured SMTP server:

   The setup of the remote SMTP server may be wrong, preventing it from receiving or processing incoming email messages. This can occur if the server is not correctly configured or if there are problems with its connectivity or authentication procedures.
3. Blacklisted or blocked server:

   The recipient’s mail server may blacklist or ban the IP address of the server delivering the email. This can occur if the sender server has a history of spamming or has been marked for questionable conduct.

Troubleshoot dsn=5.0.0 stat=service unavailable sendmail error

Consider the following actions to troubleshoot and resolve this error:

1. Check server availability:

   Check that the external SMTP server is up and running and reachable. Check its status and ensure that it is set up appropriately to accept incoming email messages.
2. Confirm DNS resolution:

   Check that the distant SMTP server’s DNS (Domain Name System) resolution is operating properly. The hostname of the server should resolve to the correct IP address.
3. Go through the Server logs:

   Examine the logs of the remote SMTP server, if available, for any error messages or difficulties that may be causing the service to be unavailable.
4. Verify sender’s reputation:

   If we are the email sender, please ensure that the IP address of the sending server is not banned or prohibited.

   To examine the reputation of an IP address, we might utilize web tools or services.
5. Contact the server administrator:

   If the problem persists, or if you are not responsible for the distant SMTP server, try contacting the server’s administrator or technical support to report the issue and request assistance.

Solution to Maillog says Service unavailable

We can use the steps given below as a soilution to the dsn=5.0.0 stat=service unavailable sendmail error:

1. Firstly, head to the etc/mail path. Check to see if the generics domain file has the same format as given below:

   
2. The genericstable file should be in the format shown below.

   

   Run the following command to map the genericstable.

   # makemap hash /etc/mail/genericstable /etc/mail/genericstable

   In to the following:

   


After this step, the relay server will accept the mail.

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Conclusion

To sum up we have now seen how to remove the dsn=5.0.0 stat=service unavailable sendmail error with the support of our tech support team.