Configuration of Sendmail in RHEL 8 involves the following steps in this article. At Bobcares, with our Server Management Service, we can handle your Sendmail issues.

Configuration of Sendmail in RHEL 8

In order to properly set up and secure the email server, we must configure Sendmail on Red Hat Enterprise Linux 8 (RHEL 8). The steps are as follows:

1. Firstly, use the following command to install Sendmail if it isn’t already installed:

2. Then, verify that the hostname for the machine is proper. Using the hostnamectl command, we can also modify the hostname:

3. The main setup file for Sendmail is typically found at /etc/mail/sendmail.mc. The m4 macro processor can be used to set it up as follows:

/etc/mail/sendmail.mc can be modified as necessary to suit our configuration. Refer to the Sendmail or RHEL documentation for individual setups as this file can be complicated.

4. In order to limit who can relay mail through the server, we can define trusted networks in Sendmail’s setup. We must make changes to the /etc/mail/access file to define trusted networks:

Then, add details such as:

Through the server, this enables hosts with IP addresses beginning with 10.0 and 192.168 to relay mail. Ensure the access database is rebuilt by running the below code:

5. Also, use the following codes to launch the Sendmail service and make it boot up automatically:

6. Make that port 25 (SMTP) is open for incoming connections if we have a firewall enabled:

7. Lastly, using the mail command or other email clients, we can send a test email to verify the Sendmail setup. Also, make sure to look for any error messages or problems in the mail logs.

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Conclusion

We may also need to install other Sendmail features, such as setting up SSL/TLS for secure communication or putting anti-spam safeguards in place, depending on our particular use case and security needs.