How to Validate Email Address in C#

1. Validate Email Address With the MailAddress Class in C#
2. Validate Email Address With the EmailAddressAttribute Class in C#

This tutorial will discuss methods to validate an email address in C#.

Validate Email Address With the MailAddress Class in C#

The first thing that comes into mind when we talk about checking formats is regular expressions. But regular expressions are relatively complex, and a lot of time is required to learn regular expressions. If you already know regular expressions, then that is the best approach for you. This tutorial will use some pre-defined methods instead of any user-defined approaches to validate email addresses in C#. The MailAddress class is used to represent an email address in C#. The constructor of the MailAddress class takes a string and formats it into an email address. We can use the MailAddress class to determine whether a given email address is valid or not. The following code example shows us how we can validate an email address with the MailAddress class in C#.

using System;

namespace email_validation {
  class Program {
    static bool IsValidEmail(string email) {
      try {
        var addr = new System.Net.Mail.MailAddress(email);
        return addr.Address == email;
      } catch {
        return false;
      }
    }
    static void Main(string[] args) {
      bool isOk = IsValidEmail("mma @gma.com");
      Console.WriteLine(isOk);
    }
  }
}

Output:

false

We defined the function IsValidEmail(email) that takes an email address as a string and returns true if the email is valid and false if the email is invalid. We used the constructor of the MailAddress class inside the System.Net.Mail namespace to create a new instance of the MailAddress class. We then compared the Address property of the MailAddress class with our email address. If the Address matches the email, the email is valid. If the Address doesn’t match the email or an exception occurs during the process, the email is invalid.

Validate Email Address With the EmailAddressAttribute Class in C#

The EmailAddressAttribute class is used to validate an email address in C#. The IsValid(email) function of the EmailAddressAttribute class returns true if the email is valid or null and false if the email is invalid. The following code example shows us how to determine whether an email address is valid or invalid with the EmailAddressAttribute class in C#.

using System;
using System.ComponentModel.DataAnnotations;

namespace email_validation {
  class Program {
    static bool validateEmail(string email) {
      if (email == null) {
        return false;
      }
      if (new EmailAddressAttribute().IsValid(email)) {
        return true;
      } else {
        return false;
      }
    }
    static void Main(string[] args) {
      bool isOk = validateEmail("mma@gma.com");
      Console.WriteLine(isOk);
    }
  }
}

Output:

true

We created the function validateEmail() that takes an email address as a string parameter and returns true if the email is valid and returns false if it is invalid. The validateEmail() function first returns false if the email is null. We created a new instance of the EmailAddressAttribute class and passed our email as a parameter to the IsValid() function of the EmailAddressAttribute class.