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Published on: by Jason Gilmore

What is a Valid Domain Name?

Domain names such as google.com, EmailReputationAPI.com, and WJGilmore.com are far easier to remember than the corresponding IP address which computers use to route communications from your web browser or email client to the corresponding servers. But it's not possible to register any domain name you want. There are rules that govern what constitutes a valid domain name. This tutorial explains what factors determine domain name validity, and how you can easily validate a domain name using EmailReputationAPI.com.

Components of a Domain Name

Believe it or not, the rules governing what constitutes a valid domain name were defined almost 40 years ago in IETF RFC 1035, published in 1987. This document, published by the Internet Engineering Task Force, defines the syntax rules used to identify a specific website or online resource. It is composed of two main parts: the second-level domain (SLD) and the top-level domain (TLD).

Valid Domain Name Syntax

To be considered valid, a domain must adhere to these general rules:

For example, the following are valid domain names:

And the following are invalid domain names:

It's important to note that domain availability may vary, and some specific domain names might already be registered by other individuals or organizations. When choosing a domain name, it's recommended to use a reputable domain registrar or search tool to check for availability and ensure you're adhering to the rules for valid domain naming.

Is .email a Valid Domain?

.email is a valid top-level domain (TLD) for domain names on the internet. It is one of the many new TLDs that were introduced as part of the expansion of domain name options beyond the traditional ones like ".com," ".org," and ".net." The ".email" TLD is intended to be used for websites and email addresses related to email communication or services. Just like other valid TLDs, you can register a domain name with the ".email" extension through domain registrars that support it.

Is .con a Valid Domain?

As of the time of this tutorial's publication, .con is not a valid TLD. However, .com is a valid TLD, and it is likely that the person who registered the domain name you are trying to reach made a typo when entering the domain name.

Is .xyz a Valid Domain?

Believe it or not, .xyz is a valid TLD. It is one of the many new TLDs that were introduced as part of the expansion of domain name options beyond the traditional ones like ".com," ".org," and ".net." The ".xyz" TLD is intended to be used for websites and email addresses related to email communication or services. Just like other valid TLDs, you can register a domain name with the ".xyz" extension through domain registrars that support it.

How to Validate Emails and Domain Names More Effectively

As the above tutorial explains, it's not possible to determine whether a domain name is valid simply by looking at it. Not only are there syntax-related constraints, but the TLD must also be valid. EmailReputationAPI is a service that provides a simple API to validate domains and email addresses. It uses a combination of machine learning and an extensive database to determine whether a domain is valid, deliverable, and reputable. It also checks if the email address is a disposable email address, uses a personal email service such as Hotmail or Gmail, or goes to other irrelevant destination. Check out the documentation at https://www.emailreputationapi.com/docs to learn more.