Set up a FQDN on a Linux server
Set up a FQDN on a Linux server
Use a .com domain for your Linux server. Set it up by registering the domain through a registrar, linking it to your server's DNS settings, and configuring any necessary hosting services.
If you manage a domain, you have the option to use it. It's best to avoid public domains registered by others, as they may cause complications. You're not limited to .com; you might choose .test, which is a reserved top-level domain. This means no one can legally sell it, but it can still be registered through your systems or networks. What are your plans for the domain? Then we can discuss the setup.
To prevent Gmail from temporarily blocking emails from your server regarding Webmin processes, ensure you're using a domain like .test. This domain often bypasses temporary restrictions.
Test operates correctly only inside your local network or systems. You must set up DNS or a hosts file to reach other hosts using the domain. For custom email domains, you need to buy a domain yourself. Anything connected to the Internet cannot work with a reserved top-level domain like .test.
Your server handles emails in a specific way. Are you connecting directly to Gmail using SMTP without any authentication? If so, you must have a valid domain, otherwise Gmail may treat you like a mail server. As @jj9987 mentioned, .test won’t function this way—it would fail when Gmail checks the domain via reverse DNS. This could lead to anti-spam actions such as being added to graylists. Ideally, use an authenticated email client instead.