Email address validation using ASP.NET MVC data type attributes

If you are using .NET Framework 4.5, the solution is to use EmailAddressAttribute which resides inside System.ComponentModel.DataAnnotations.

Your code should look similar to this:

[Display(Name = "Email address")]
[Required(ErrorMessage = "The email address is required")]
[EmailAddress(ErrorMessage = "Invalid Email Address")]
public string Email { get; set; }

Try Html.EditorFor helper method instead of Html.TextBoxFor.

You need to use RegularExpression attribute, something like this:

[RegularExpression("^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$", ErrorMessage = "E-mail is not valid")]

And don't delete [Required] because [RegularExpression] doesn't affect empty fields.

if you aren't yet using .net 4.5:

/// <summary>
/// TODO: AFTER WE UPGRADE TO .NET 4.5 THIS WILL NO LONGER BE NECESSARY.
/// </summary>
public class EmailAnnotation : RegularExpressionAttribute
{
    static EmailAnnotation()
    {
        DataAnnotationsModelValidatorProvider.RegisterAdapter(typeof(EmailAnnotation), typeof(RegularExpressionAttributeAdapter));
    }

    /// <summary>
    /// from: http://stackoverflow.com/a/6893571/984463
    /// </summary>
    public EmailAnnotation()
        : base(@"^[\w!#$%&'*+\-/=?\^_`{|}~]+(\.[\w!#$%&'*+\-/=?\^_`{|}~]+)*"
            + "@"
            + @"((([\-\w]+\.)+[a-zA-Z]{2,4})|(([0-9]{1,3}\.){3}[0-9]{1,3}))$") { }

    public override string FormatErrorMessage(string name)
    {
        return "E-mail is not valid";
    }
}

Then you can do this:

    public class ContactEmailAddressDto
    {
        public int ContactId { get; set; }
        [Required]
        [Display(Name = "New Email Address")]
        [EmailAnnotation] //**<----- Nifty.**
        public string EmailAddressToAdd { get; set; }
    }

I use MVC 3. An example of email address property in one of my classes is:

[Display(Name = "Email address")]
[Required(ErrorMessage = "The email address is required")]
[Email(ErrorMessage = "The email address is not valid")]
public string Email { get; set; }

Remove the Required if the input is optional. No need for regular expressions although I have one which covers all of the options within an email address up to RFC 2822 level (it's very long).

[Required(ErrorMessage = "Please enter Social Email id")]
    [DataType(DataType.EmailAddress)]
    [EmailAddress]
    public string Email { get; set; }

Used the above code in MVC5 project and it works completely fine with the validation error. Just try this code:

   [Required]
   [Display(Name = "Email")]
   [EmailAddress]

   [RegularExpression(@"^([A-Za-z0-9][^'!&\\#*$%^?<>()+=:;`~\[\]{}|/,₹€@ ][a-zA-z0- 
    9-._][^!&\\#*$%^?<>()+=:;`~\[\]{}|/,₹€@ ]*\@[a-zA-Z0-9][^!&@\\#*$%^?<> 
        ()+=':;~`.\[\]{}|/,₹€ ]*\.[a-zA-Z]{2,6})$", ErrorMessage = "Please enter a 
   valid Email")]


   public string ReceiverMail { get; set; }

As per the above this will fix server side validation of an Email Address:

[Display(Name = "Email address")]
[Required(ErrorMessage = "The email address is required")]
[EmailAddress(ErrorMessage = "Invalid Email Address")]
public string Email { get; set; }

However...

If you are using JQuery client side validation you should know that the Email validates differently server side (model validation) to client side (JQuery validation). In that test@example (a top level domain email address) would fail server side but would validate fine on the client side.

To fix this disparity you can override the default client side email validation as follows:

$.validator.methods.email = function (value, element) {
    return this.optional(element) || /^[a-z0-9._]+@[a-z]+\.[a-z.]+/.test(value);
}

[RegularExpression(@"^[A-Za-z0-9]+@([a-zA-Z]+\\.)+[a-zA-Z]{2,6}]&")]

I have had this issue as well, you can try this it's works for me

[RegularExpression("[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?", ErrorMessage = "Email is not valid")]

Scripts are usually loaded in the end of the html page, and MVC recommends the using of bundles, just saying. So my best bet is that your jquery.validate files got altered in some way or are not updated to the latest version, since they do validate e-mail inputs.

So you could either update/refresh your nuget package or write your own function, really.

Here's an example which you would add in an extra file after jquery.validate.unobtrusive:

$.validator.addMethod(
    "email",
    function (value, element) {
        return this.optional( element ) || /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/.test( value );
    },
    "This e-mail is not valid"
);

This is just a copy and paste of the current jquery.validate Regex, but this way you could set your custom error message/add extra methods to fields you might want to validate in the near future.

I have had this issue as well, and when you use [EmailAddress] annotation it allows them to put in a email like this test@email and does not require an actual .com. I found the best way to do this is like this. I didn't actually write this RegEx I found it on another question in Stackoverflow, or maybe one I asked lol. However the regular expression says before the @ you can add letters and numbers with a hyphon (-) and but no special characters. The @ sign you have to add something like gmail, aol, live, yahoo, etc... It haves to have at least one character after the @ sign. Then at the period or dot . you must put something no less than two character like .com, .net, .org, .infor I don't know many emails ending with .au which means Australia just in case. Now if you want to break it down you would have to go to this site RegEx for better explanation at the bottom.

[Required, MinLength(1), DataType(DataType.EmailAddress), EmailAddress, MaxLength(50), Display(Name = "Email")]
[RegularExpression(@"^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$", ErrorMessage = "Please enter a valid e-mail adress")]
public string EMail { get; set; }